SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
Actions are now shared between menu bar and toolbar. Adds an edit
menu to complement toolbar actions. Glyphs are now passed as ints
instead of u8s; fixes Latin Extended+ glyphs failing to update in
real time on map. Converts weight and type to more human-readable
combo box lists. Selected glyph now scrolls into view on load.
Adds cut, copy, paste and delete to GlyphEditor. Font preview has
moved to a separate resizable ToolWindow. Font metadata can now be
hidden. FontEditor and glyph widgets can now be re-initialized
instead of resetting window's main widget after loading new fonts.
