Split wx_fsqlf into several files

Separate  and .
Also movout drop-n-drag target class into separate file.
 class coud not be moved into separate file,
because there is compile or link error after that.
Fix monospace fonts

Get rid of old macro (which was at best a workaround)
and use setFont from wxWindow
Fix makefile for compiling windows version

When spliting gui source code into several files,
mistakes were introduced, and makefile worked only for building
linux version
Add message if max char limit reached