implement #34

Tested on Linux only (will test on windows soon)
#34 improve log messages
Bump version to 2.4.0a1
#34 Add more debug messages to trace #33
#33 Bump version to 2.4.0a2 (alpha 2)
#34 more debug messages
#33 create handle for stdin on windows
#33 Bump version to 2.4.0a3
Porting to pyQode 2.0 and PyQt5 (#36)

The IDE is now working fine under pyqode 2 and PyQt5 but I have to redesign the preferences dialog
Allow failure for PyQt5 env

(PyQt5 not installed on travis)
Travis: Install pyqode.core from dev branch
Restore test files to their master version

(they were modified unintentionally)
Fix margins
Improve UI (not more resize when going back to home page)

also show code editor more quickly
Working on the new settings dialog

(I should have a look at http://stackoverflow.com/questions/2480773/qt-styling-qtabwidget to improve styling)
Implement the new settings dialog

(nearly finished, remains a few polishing)  #36
Rm .cache
Update to latest pyqode version where style/action/settings module
has been removed
#36 Improve recent files list
Add mac support

fix #37