wip on replacing session with account
Renaming classes (WIP).
Merge remote-tracking branch 'origin/refactor' into rename

Conflicts:
	include/maidsafe/account.h
	include/maidsafe/detail/account_handler.h
	include/maidsafe/private_client.h
	src/maidsafe/account.cc
	src/maidsafe/tests/account_handler_test.cc
	src/maidsafe/tests/private_client_test.cc
Initial API updates complete.
Made PrivateClient::Login and CreateAccount asynchronous.  Avoided passing AccountGetter by shared_ptr.
minor cleanup
Moved Account and AccountGetter to detail namespace.  Added Logout function to PrivateClient.
minor typo
Changed Login/CreateAccount to return futures to unique_ptr<PrivateClient>.
Merge branch 'refactor' of github.com:maidsafe/MaidSafe-API into refactor

Conflicts:
	src/maidsafe/tests/private_client_test.cc
wip on debugging account getter destruction
Added tests to check duplicate account creation and invalid login error codes. Copied Fraser's ThrowAs helper method to utils.h.
Minor test fixes.
minor fix for osx build
Another minor test fix.
Merge branch 'refactor' of github.com:maidsafe/MaidSafe-API into refactor
Fixed destruction order of AccountGetter members, specifically Routing.
switched expected error code for duplicate create account
fix for intermittent crash on Account getter test.