Fixing issue #258, bad keyfile permissions.

This spits out a warning to the console, but ideally it would also
issue a warning to the GUI for those who didn't start it from the
console. N.B. the warning is a one shot thing, since it fixes the
problem in a way essentially undetectable in the future, so it
should be done right if it is to be done at all.
Maybe we should even disable all keys automatically if the keyfile
is found in an insecure state.
Merge branch 'master' of github.com:Atheros1/PyBitmessage
Merge branch 'master' of github.com:Atheros1/PyBitmessage
Merge branch 'master' of github.com:Bitmessage/PyBitmessage
Merge branch 'master' of github.com:Bitmessage/PyBitmessage
Fix #263 & #262: insecure keyfile permissions.

* Added conditional to keyfile fix code that excludes windows.
* Cleaned up old keyfile permissions fix.
* Added umask (not conditional against Windows, because I don't think that is necessary).
Make warning message more specific.
Merge branch 'master' of https://github.com/Bitmessage/PyBitmessage into keyfile_perm_fix
Added a class for background working
renamed class BGWorker to bgWorker
renamed class BGWorker to bgWorker
Made gevent happy with PyQt.
Removed a blank line.
Sleep more , save more.
Sleep more , save more.
Put setDaemon inside init.
Made it compatible with gevent 1.0dev version.
Real logging, please incorporate into new and existing code.
replace acquire lock by 'with' statement
Merge branch 'master' of github.com:Bitmessage/PyBitmessage