* Adapted from prior submissions by Tobias Mueller and Jacob Adams.
* key_import function added to gpg.core.Context().
* Two example scripts added to to examples/howto: import-key-file.py
  imports keys from a local file and import-keys.py accesses the SKS
  keyserver pool using the requests module to search for keys
  (includes check for key IDs which may not include the leading 0x).
* Added documentation demonstrating the use of the key_import()
  function with a large number of keys matching one domain (eff.org;
  the example shows how EFF staff are following their own advice
  issued last month).