License update (Closes: #27):

 * Updated licensing headers (GPL-3+ & OpenSSL exception)
 * Replaced LGPL-3 license text with GPL-3 in file "LICENSE.GPL3";
   moved unnecessary info to "README.md".
 * Removed unnecessary information from headers; kept only relevant
   copyright/license statement and backlink.
 * Explicitly mention that donation address is for Bitcoins
   to avoid confusion with other crypto-currencies.
 * Readme.md
   + included "intention statement" formerly used in headers.
   + mention donation address only once.
   + "normalised" email address.
   + mentioned BTC-E as well as MtGox; corrected some typos.
Merge pull request #118 from onlyjob/testing

License update (Closes: #27):