Change MainWindow into a Singleton class for easier access of the instance across other classes, minor bug fix
Find Next/Previous menu actions added, replace functionality.
Integrate patch for bug #1016847 into this branch
Minor change type of fileAlreadyOpened to int so it can tell us the tab index the file is located at.... Switch to already opened tab if only one file is opened.
Minor bug fix
Always continue search from cursor position
Merge pull request #9 from Teklad/object_rewrite

Search/replace and integration of patch for bug #1016847