Release 0.8.5 "Stone" - Emergency keyboard fixups

The major changes in 0.8.4 caused some damage to keyboard handling code that require a few emergency fixes.

Bug fixes

• Fix incorrect selection of lowercase characters
• Fix the location of exp and log10 in 42style and true42 keymaps.
• Do not enter interactive stack if reaching leftmost position of the text editor.

Full Changelog: v0.8.4...v0.8.5