Added support for {SHA} passwords (ticket #50). Note: use of {SHA} passwords is discouraged as {SHA} password scheme is vulnerable to attacks using rainbow tables. Use of {SSHA}, $apr1$ or crypt() algorithms as supported by OS is recommended instead. The {SHA} password scheme support is added to avoid the need of changing the scheme recorded in password files from {SHA} to {SSHA} because such a change hides security problem with {SHA} passwords. Patch by Louis Opter, with minor changes.