fix account type checkings

Account::getAccountType() returns a raw pointer on char,
but we use it with simple operators like == or != to check
the semantic behind. This results to pointer comparaison
and not "string" comparaison, causing many bugs.

Fixed by changing the comparaison operators by "strcmp" function.

Change-Id: I74baba083af0159d445c1505ddd5df55e6ca4fa7
Tuleap: #1575
Reviewed-by: Philippe Gorley <philippe.gorley@savoirfairelinux.com>