`gui.set_theme()` accepts key-value argument pairs for theme properties to set.
Always emit `events.LANGUAGE_MODULE_LOADED`; modules/textadept/mime_types.lua
Creates an empty language-specific module if none exists. This enables users to
add keys and snippets for any lexer without an existing language-specific
module. It also allows themes to override styles for any lexer.
Remove theme selection since it does not persist.
Encourage calling `gui.set_theme()` from *~/.textadept/init.lua* instead.
Do not allow transposing in empty buffer; modules/textadept/editing.lua
Use lfs 1.6.2 instead of latest master; src/Makefile