ebuild: remove bash-4 specific code

fixes #388
Merge pull request #394 from karolherbst/ebuild

ebuild: remove bash-4 specific code
Merge pull request #407 from matthiaskrgr/optimize_graphics

optimize graphics using matthiaskrgr/image_optim

stuff done by this commit:
1. conversion of some files to grayscale pngs + drop of PLTE table
2. removement of iTXt and eTXt tags created by adobe software
3. removement of "created with photoshop" tags

the image raw data does not seems to be touched.
test: remove getAppPath test in UtilLinux_test

this function will be tested by "GUI" Test cases as well.

If it's working desurium will start correctly, if not then not.
It doesn't make sense to test this function the same way it was implemented.
partially revert "Travis:"

the update of all needed package can fail unter some circumstances.
See here: https://travis-ci.org/karolherbst/Desurium/builds/4325989

We should install only the missing ones
Merge pull request #413 from karolherbst/bug392

test: remove getAppPath test in UtilLinux_test
Merge pull request #414 from karolherbst/travis

partially revert "Travis:"
test: tidy up UtilLinux_test

this should eliminate test failures throw std::cout (for example if some xdg aren't installed)
Merge pull request #416 from karolherbst/travis

test: tidy up UtilLinux_test

we should clean up test anyway. Print something to std::out doesn't make sense.

Instead we should check fixed values against function results. After the 0.8 release we should create a lot of tests to stabilize desurium.
fix compile compatibility with wxWidgets-2.9.4
uicore: fix cef bug with wxGTK-2.9.4

everytime the window was resized to a bigger size some of the background had to be redrawn, which resulted in the disappearing of CEF. Just redraw CEF if something happens to gcWebPanel
Merge pull request #390 from karolherbst/bug288

some wxWidgets 2.9.4 stuff