fix always_allow_SSL bug [thanks, Tolleiv Nietsch!]

add sslPort option

added always_allow_SSL constant

when checking for an SSL connection, we now look at the superglobal $_SERVER instead of $GLOBALS['HTTP_SERVER_VARS']. $_SERVER is available since PHP 4.1 and the preferred method to access these variables, as the “long arrays” (HTTP_*_VARS) are depreciated for performance reasons and may be disabled in installations running on PHP 5, and the variables we need are not provided by typo3's t3lib_div::getIndepEnv() [thanks, Johnny, for researching this]

added https_enforcer.ssl_proxy constant and support for SSL proxys “invisible” to typo3

State changed to beta as we have started to do some development (and will do some more soon, see ToDo) and thus may introduce bugs

changed the way https_enforcer separates the (un)secure_typo3_root from the rest of the path so that it works well with the realurl extension