initial commit for text language parser infrastructure
Merge branch 'master' of git://github.com/DenisKogutich/qreal
Merge branch 'master' of https://github.com/qreal/qreal
Merge branch 'master' of https://github.com/qreal/qreal
Merge branch 'master' into textLanguage

Conflicts:
	plugins/robots/interpreters/commonTwoDModel/src/engine/view/d2Form.ui
regexp-based lexer, some parser infrastructure
added connection to lexemes
redefinition of tokens
keywords, lua-specific lexemes
error reporting
small refactoring
Lua version updated to 5.3, full support for numeric literals
- fixed bug that allowed integers to be lexed as floats sometimes
- some cleanup
support for string literals
- fix for multiline strings connection
- fix for lexer hanging up if not able to recover
- support for comments
updated comment
Merge branch 'master' of https://github.com/qreal/qreal into textLanguage

Conflicts:
	qrtest/unitTests/qrutilsTests/qrutilsTests.pro
	qrutils/qrutils.pri
- refactored lexer to use traditional terminology
- added grammar and started to write parser
Some black magic with parser combinators
parsera are passed by value instead of by reference, ast now uses shared pointers, it shall make memory management more clear and automated