Use icons for counters in status bar
Include active requests in the pending requests count.

Counter was 0 if request queue was empty but Picard was still waiting for replies,
with this change, counter is set to 0 only if no active request left.
Reduce spaces between counters.
Remove incorrect author from header.
Merge remote-tracking branch 'upstream/master' into status_icons
Use a green down arrow as download icon instead of globe.

In 16x16 globe is too complex, arrow is much more legible.
Merge pull request #134 from zas/status_icons

Display icons with tooltip instead of text for counters in status bar
Add @throttle decorator to reduce the number of GUI updates
Merge pull request #126 from mwiencek/throttle-gui

Add @throttle decorator to reduce the number of GUI updates
functools.partial is 2.5+
Copy value list in Metadata.update
Deprecated failUnlessEqual() -> assertEqual()

http://docs.python.org/2/library/unittest.html#deprecated-aliases
Deprecated failIfEqual() -> assertNotEqual()

http://docs.python.org/2/library/unittest.html#deprecated-aliases
Deprecated failUnlessRaises() -> assertRaises()

http://docs.python.org/2/library/unittest.html#deprecated-aliases
Deprecated failUnlessAlmostEqual() -> assertAlmostEqual()

http://docs.python.org/2/library/unittest.html#deprecated-aliases
Handle configuration file versions.

version_info was renamed PICARD_VERSION
version_string was renamed PICARD_VERSION_STR
short version string is stored in PICARD_VERSION_STR_SHORT (for display)

Hooks can be created to handle upgrades (ie. options renaming), see config.register_upgrade_hook() and config.run_upgrade_hooks()
PEP8 compliance fixes
Merge pull request #139 from zas/deprecated_unittest_aliases

Replace deprecated unittest aliases
pep8 fixes
Merge pull request #140 from zas/pep8

PEP8 compliance fixes