translations update 2013-04-08

- updates for bitcoinstrings.cpp and bitcoin_en.ts
- changes help text for -rpcthreads to match -par
- fix a small glitch with -par to be "-par=<n>"
overhaul of the testnet icon (green color) and the toolbar icons

- redefined the green color
- created new toolbar icons
- updated the assets-attribution.txt

Signed-off-by: Jonas Schnelli <jonas.schnelli@include7.ch>
fix mac specific button modification on addressbookpage

- continue the mac behavior of clearing button icons (because it's unusual on mac apps)
- fix: new button variable names, new buttons (verifyMessage, signMessage)

Signed-off-by: Jonas Schnelli <jonas.schnelli@include7.ch>
Merge pull request #2498 from jonasschnelli/addressbookpage_mac_fix

fix mac specific button modification on addressbookpage
better quality windows .ICO icon file

- icon quality of the win icon of <256px resolutions are now much better

Signed-off-by: Jonas Schnelli <jonas.schnelli@include7.ch>
move COPYRIGHT_YEAR to clientversion.h

- this allows usage of that information also in other places (e.g. splash
  screen)
use the new COPYRIGHT_YEAR macro in bitcoin-qt.rc

- this reduces the places, where we need to change the year further
fix bitcoin-qt.rc not showing up in Qt Creator
Merge pull request #2487 from Diapolo/translations

translations update 2013-04-08
Merge remote-tracking branch 'jonasschnelli/new_icons' (#2497)

Conflicts:
	doc/assets-attribution.txt
Merge pull request #2503 from Diapolo/copyright-year

new COPYRIGHT_YEAR macro in clientversion.h
Add test patches for pull-tester to contrib/
Merge pull request #2514 from TheBlueMatt/master

Add test patches for pull-tester to contrib/
Use a uint256 for bnChainWork

Every block index entry currently requires a separately-allocated
CBigNum. By replacing them with uint256, it's just 32 bytes extra
in CBlockIndex itself.

This should save us a few megabytes in RAM, and less allocation
overhead.