Release 0.7.7 "Forgiving" - Units in equations

This release keeps marching towards full support for an equation library. The primary focus was support for units in equations.

New features

• solver: Accept equations in solver menu
• solver: Add shortcut to solve an equation from the library
• solver: Display the current equation above the stack
• solver: Solve expressions containing units
• solver: Add units for solver variables when entering them
• equations: Add option to list variables with units
• programs: Enforce numerical values for solver / plotter
• constants: Implement programmatic lookup
• fonts: Add support for fixed-width digits
• keyboard: Interpret ASN as AsNumber (convert to decimal)
• complex: Allow insertion of angle while entering phasors
• complex: Implement auto-complex promotion
• graph: Render abs(X) with bars (e.g. |X|)
• functions: Automatic simplification of expressions

Bug fixes

• arithmetic: Avoid null-dereference in complex operations
• help: Close help file if topic not found
• solver: Do not store tag for tagged values
• graph: Gracefully fallback if fraction integral part does not render
• units: Avoid null-dereference if unit simplification fails
• units: Count parentheses while parsing units
• put: Fix null-dereference checking the index
• fractions: Do not render two negative signs in graphical mode

Improvements

• cycle: Update behaviour for several data types
• menu: Replace abs with |z| in complex menu
• ui: Micro-optimization to avoid reading object type twice
• parser: Accelerate and improve object parsing
• recorder: Add recorder entries for evaluation
• build: Remove any leftover references to Intel decimal library
• tests: Add ▶ entry in tests
• tests: Increase default wait time to 1000ms
• tests: do not error out if teval takes less than 100ms
• equations: Rename PerfectGas equation to IdealGas
• menus: Adjust size of menus to make descenders visible
• solver: Replace SolverPrecision with SolverImprecision