DB48X: HP48-like RPL implementation for DM42

[c3d]

Release 0.7.0 is out. https://github.com/c3d/DB48X-on-DM42/rel...tag/v0.7.0

This release introduces a few major improvements, including graphical rendering of equations and matrices, the `Show` command to display large objects full-screen, customizable constants, and date-related operations.

New features

* Graphical rendering of equations, fractions, matrices, vectors and lists. In graphical rendering mode, variables are showin in italics.
* Constants in the `ConstantsMenu`, split into categories, and loading from an optional `config/constants.csv` file, in a way similar to what existed for units.
* Inverse trigonometric functions (`asin`, `acos` and `atan`) now produce unit objects with the current angle mode as a unit. This can be configured by the `SetAngleUnits` / `NoAngleUnits` flags.
* `Cycle` (EEX key) now cycles between angle units.
* `R→D` and `D→R` commands to convert between degree and radian in a purely numerical way (no unit). This is for compatibility with HP.
* Add `→Deg`, `→Rad`, `→Grad`, `→πr` commands, which convert a number to the target unit using current angle mode, and convert an angle to the target angle unit.
* Conversion from DMS to HMS and from HMS to DMS
* Rendering of dates: `19681205_date` renders as `Fri 5/Dec/1968`,
with a format configuration using the same flags as for the header. Note that the date format is `YYYYMMDD`, _not_ the same as on HP calculators. This allows `YYYYMMDD.hhmmss` for dates with time.
* `Date` and `Time` command to return the current date and time. Additionally, `DateTime` returns both date and time, and `ChronoTime` returns the time with 1/100s precision.
* `→Date` and `→Time` commands to set the system date and time
* `Date+`, `DDays` and date arithmetic using `+` or `-`, using day units for the results. As an extension relative to HP calculators, these will accept fractional days, or other time units. For example, adding `1000000_s` to `19681205_date` generates a date with time result, `Tue 16/Dec/1968, 13:46:40`
* `JulianDayNumber` and `DateFromJulianDayNumber` commands to convert between dates and Julian day numbers. These commands also accept fractional input.
* `Show` command showing a full-screen graphical rendering of the result on the stack. The resut is size-adjusted. For example, you can display all digits in `200!`. If the result does not fit on the screen, you can scroll using the _◀︎_ and _▶︎_, as well as _8_, _6_, _4_ and _2_. The maximum pixel size for `Show` is set by `MaxW` (default is the width of the LCD), the maximum height is set by `MaxH` (default is 2048 pixels).
* `AutoScaleStack` and `NoAutoScaleStack` settings to automatically adjust the font size for the stack elements.
* Support for system flags -20 to -26 (infinite results, overflow and underflow).


Bug fixes

* simulator: Adjust DMCP month off-by-one error
* Repair insertion of `while` loops and similar commands on the command line
* Use stack format when drawing an object with `DrawText` (`DISP`)
* Arithmetic on unit objects no longer auto-simplifies, e.g. `1_s 1_s
-` returns `0_s` and not `0`.
* Perform computations for `→Q` using integer values, which avoids an issue where increasing the number of iterations with an unachievable precision could prodduce `1/1` as the fractional result.
* Repair auto-simplification for `i*i=-1`
* Display a negative mixed fraction as `-1 1/3` and not `1 -1/3`.
* Do not insert `()` after a multiplication in algebraic mode
* Accept units and tagged objects in `PolarToReal` and `RealToPolar`
* Accept angle units as input for `→DMS`
* Off-by-one clipping error in header, erasing the shift annunciator
* Fix help for `FC?` (incorrectly stating that it tested for flat set)
* Lookup units and constants in a case sensitive way
* Fix labels for `ExpFit` and `LinFit` in `RegressionMenu`.


Improvements

* tests: Adjust tests to match bugs fixed in v0.6.5
* dms: Accept entering minutes without third dot, e.g. `1.2.3 ENTER`
* menus: Split the Time, Date and Alarm menus
* Split rendered objects at space boundaries. This notably ensures that large numbers are split at digit grouping boundaries, and makes it possible to display larger programs on the stack. The rendering of programs and matrices/vectors/lists has also been fine-tuned.
* The "white circle" glyph has a thicker border, makes it more readable in menus.
* doc: Update the list of unimplemented features
* menus: Draw a white circle for disabled flags, and allow the menu function to toggle the flag. This made it possible to reduce the number of menu entries for flag-heavy menus.
* Mixed fractions are now the default, as opposed to improper fractions
* doc: Improve the quickstart guide
* doc: Improve the documentation for sin, cos and tan
* tests: Make it possible to interrupt a running test
* help: Skip HTML tags, e.g. <video>
* simulator: Add screenshot capability, and reduce window height
* menus: `ToolsMenu` selects time, date or angle menu based on units