Move inner script in options_dialog.xul to new JS file
Add new option "Open in Firefox" to launcher setting
Alter line endings from DOS-style to Unix-style (options.xul)
Let options dialog manage openInFx option and fix some bugs related to openInFx option
Support openInFx option on saving prefs and fix bug on loading prefs
Open specified file in current window if `openInFx` option is enabled
Merge: new option "Open in Firefox" on launcher setting