Merge tag '0.2' into develop

Release 0.2
simplified format string parsing
better string representation of doc tokens
simplified format string parsing, step 2
added validation to edit_dialog
error handling tests
removed deprecated code
added message dialog helper module
[strfmt_dialog] get output directly from preview in direct editing mode
[strfmt_dialog] warn user when exiting direct editing mode
[gui] set wm hints for dialogs
[gui] emit set-state event when resetting state
added flag token handling
Docstring parser flag handling
added tests for flag lexing/parsing
Format string parser flag handling
GUI for flag fields
updated TODO
added new snippets to default.clisnips
Syntax highlighting for flags