Add ability to set metadata variables in the language files.
Use the LANGUAGE_DISPLAY_NAME metadata variable value in preferences to
show the languages.
Metadata variables are defined in the first section of a language file,
i.e. the comments at the beginning of the file. At most one variable can
be defined per line. The definition takes the following format:
#<header><whitespace>@<key>=<value>
where:
<header> is any sequence of non-whitespace characters
<whitespace> is any non-empty sequence of whitespace characters
<key> is the metadata key name
<value> is the metadata value
For example,
#101 @LANGUAGE_DISPLAY_NAME=English (US)
defines a metadata key "LANGUAGE_DISPLAY_NAME" with value
"English (US)". Lines that do not match the format are ignored.
updated magyar shortcuts
added ignoring Ctrl categoryButtonToggled if is mouse click for more consistent shortcut functions
fixed missing windows shortcut
