Bump version numbers for 0.8 release

Version numbers changed from 0.7.99 to 0.8.0
Set CLIENT_VERSION_IS_RELEASE to remove pre-release warning
Updated copyright in COPYING and doc/READMEs to 2013
Updated doc/release-notes.txt
Signrawtransaction shouldn't require redeemScript for non-p2sh txins.

The redeemScript functionality broke plain offline signing, this
change makes it only look for that parameter when signing a p2sh
input.
Do not call ResendWalletTransactions when reindexing, importing or on IBD

Calling ResendWalletTransactions when reindexing, importing or on IBD spams
other nodes with our old transactions, because they become unconfirmed.
Bugfix CValidationResult for BIP30 + add DoS
Merge pull request #2259 from Criptomonedas/dontresend

Do not call ResendWalletTransactions when reindexing or importing
Merge pull request #2264 from gmaxwell/signrawtransaction_for_regular_missing_txins

Signrawtransaction shouldn't require redeemScript for non-p2sh txins.
Merge pull request #2279 from sipa/cvrbip30

Bugfix CValidationResult for BIP30 + add DoS
Merge commit 'd38c6488d067c2e88726e2ca99bc76fd67dab49b'