fix major bugs in Find and Search in Project functionality.

fix case sensitive and regexp search, remove duplicating code

Signed-off-by: Andrey Skvortsov <andrej.skvortzov@gmail.com>

fix issue with non-updated button 'generated IECCode' after Build and Clean

increase dialog size for edit SFC transition, so buttons are visible

fix issue that sometimes period for cyclic task wasn't saved.

This is complete fix for the problem described in 8626bba.

add first steps example, that shows how use all IEC 61131 languages

fix issue with empty frame with generated ST code

fix not saving location address from variable panel

this regression was introduced by commit 3518d10

add $(Beremiz installation)/mingw/bin in PATH on Windows platform

This fixes issue if multiple gcc installation are found in user's
PATH. Now gcc from Beremiz is used by default.