DB48X: HP48-like RPL implementation for DM42

[c3d]

https://github.com/c3d/DB48X-on-DM42/rel...tag/v0.6.3

The focus of this release was to reactivate the test suite and fix the problems that were found activating it.





### New features:

* HMS and DMS operations
* unit: Rendering of `dms` and `hms` units
* Allow `·` as a multiplication sign in equations
* ui: Display 'E' cursor inside parentheses
* graphics: Accept based integers as position for `DrawText`
* complex: Add setting to switch between `2+3i` and `2+i3`.

### Bug fixes:

* decimal: Fix precision loss for addition with carry
* Base: limit range of bases to 2-36
* files: Do not add a trailing zero when reading a text file
* decimal: Adjust `MinimumSignificantDigits` behaviour
* units: Do not auto-simplify `1.0` during conversion
* decimal: Normalize parsed numbers
* solver: Fix sign error in epsilon exponent for solve/integrate
* parser: Accept `x!` as input
* simulator: Avoid faulty break-through in switch statement
* complex: Make tag higher-priority than complex
* editor: Adjust cursor and select correctly during replace
* decimal: Fix display of 0.2 in NoTrailingDecimal mode
* complex: Save `this` in a GC pointer when it can move
* arithmetic: Do not fail because of surrounding error
* decimal: Clamp int32 conversions from decimal
* commands: Parse `exp10` correctly in expressions
* decimal: Avoid infinite loop computing `expm1`
* ids: Do not allow parsing of structures
* dmcp: Make sure the tests don't block on `wait_for_key`
* decimal: Use correct angle unit for negative gamma values

### Improvements:

* settings: Add classes that save/restore a given setting
* Add `XSHIFT` to shift to XSHIFT state directly
* Add NOSHIFT constant to simplify test writing
* ui: Add a variant of `close_editor` without trailing zero
* decimal: Cache gamma_ck values (accelerate gamma and lgamma)
* Replace magic constant `-1` with `EXIT_PGM`
* doc: Record performance data for 1000 iterations of SumTest
* decimal: Add tracing for gamma / lgamma function

### New tests:

* Add tests for arithmetic truncation on short bitsizes
* Add tests for on-line help
* Add test for plotting flags
* Add test for Unicode to text conversions
* Add test for rectangular complex display options
* Add tests for plot scaling functions
* Add tests for the sorting functions
* Add test for parsing text with quotes inside
* Add test for file-based `STO` and `RCL`
* Add test for 2^256 computation (buf #460)
* Fix indentation of `[PASS]` or `[FAIL]` for UTF8 characters
* Add tests for units and conversions
* Add a keyboard test checking the single-colon insert in text
* Add test for i*i=-1 auto-simplification
* Add basic test for numerical integration
* Add test for fraction formats
* Add solver test
* Add missing tests
* Add test for immediate `STO` (#390)
* Add tests for the `Cycle` command
* Add test for catalog feature
* Add test for "smart" keyboard shortcuts introduced in 0.4.6
* Add regression test for #371
* Add tests for editor operations
* Test stack operations
* Add test for `GXor`, `GOr` and `GAnd`
* Add test for `ResetModes`
* Add plotting test for every decimal function
* Add image checking for graphical tests
* Add tests for graphic and text drawing commands
* Make it possible to individually run tests.
* Add plotting tests
* Add test parsing the various spellings for commands