CWallet::TopUpKeyPool() takes optional pool size argument

Also, GetKeyPoolSize() now returns an accurate type, unsigned int.
RPC: keypoolrefill gains optional size parameter
Compile into build_test when creating bitcoin-qt_test
Removed duplicate files.

Left behind after the change to Markdown.
Merge pull request #2899 from super3/master

Removed duplicate /doc files.
Merge pull request #2877 from gavinandresen/qt_unittest_makefile

Compile into build_test when creating bitcoin-qt_test
Merge pull request #2776 from jgarzik/keypoolsize

RPC: keypoolrefill now permits optional size parameter, to bump keypool