Change; fix; feature

* Add ability to disable automatic transaction in BSqlDatabase when creating DB from schema
* Fix BAbstractCodeEditor highlighting (do not reset extra selections when rehighlighting brackets if not needed)
* Add ability to set default command handler in BTerminal
Optimize extra selections rehighlighting

For ~5000 selection ranges (length mostly 1-3) selection changing time
changed from ~200-300ms to 70-80ms (on Core i3 2100)
Add BTextToole::parseOptions function
Fix struct/method names

* Replace "Interval" by "Segment" in code editor classes
Fix bugs
Fix BTerminal
Fix plugin system
Fix BAbstractFileType autocompletion
Fix code editor extra selections
Fix bugs
Add methods to BeQt namespace
Improve plugin settings system
Update copyright info
Fix BLineEdit
Fix code editor search results highlighting
Update version
BeQt v4.0.0-beta3