Workers get idle priority.
Removed extraneous import.
Messy hack to kill busy child processes on exit.
Moved workaround code slightly.
Merge remote-tracking branch 'upstream/master'

Conflicts:
	src/proofofwork.py
	src/shared.py
Trying to enable multicore PoW with single core as a fallback when it's a problem.
Removed an extraneous conditional import.
Merge branch 'master' of https://github.com/Bitmessage/PyBitmessage
Wait for PoW processes to exit before returning a result. Hopefully not needed.
launched autopep8 --in-place --recursive --jobs=0 -aaaaa __init__.py
fixed typo + translation files
fixed typos + translation files
fixed typo in translation file
fixed typo in GUI
fixed typo + translation file
fixed french typo
fixed french typo
function _translate - lighter code

replace QtGui.QApplication.translate with _translate
fixed "libpng warning: iCCP: known incorrect sRGB profile" error

=== before ===
(find . -iname '*.png' -type f -exec identify -verbose '{}' +) |& grep 'known incorrect sRGB profile'
identify: iCCP: known incorrect sRGB profile `./can-icon-24px-green.png' @ warning/png.c/MagickPNGWarningHandler/1830.
identify: iCCP: known incorrect sRGB profile `./greenicon.png' @ warning/png.c/MagickPNGWarningHandler/1830.
identify: iCCP: known incorrect sRGB profile `./can-icon-24px-yellow.png' @ warning/png.c/MagickPNGWarningHandler/1830.
identify: iCCP: known incorrect sRGB profile `./redicon.png' @ warning/png.c/MagickPNGWarningHandler/1830.
identify: iCCP: known incorrect sRGB profile `./can-icon-24px.png' @ warning/png.c/MagickPNGWarningHandler/1830.
identify: iCCP: known incorrect sRGB profile `./can-icon-24px-red.png' @ warning/png.c/MagickPNGWarningHandler/1830.
identify: iCCP: known incorrect sRGB profile `./can-icon-16px.png' @ warning/png.c/MagickPNGWarningHandler/1830.
identify: iCCP: known incorrect sRGB profile `./yellowicon.png' @ warning/png.c/MagickPNGWarningHandler/1830.
updated icons file

pyrcc4 bitmessage_icons.qrc -o bitmessage_icons_rc.py