Bootstrap/timezone: do not enforce config

The current way forces people running a correctly configured PHP
to configure timezone once again in Icinga Web. We want LESS config,
so this tries to fix this.
Authentication\Manager: fix fromRemoteUser boolean

This used to be always true in case an autologin backend was enabled.
We only have a REMOTE_USER if there is such.
FilterQueryString: just cleaning up a little bit
FilterQueryString: fix sub-expression parsing

In a string like !(b=c)&a=d the parser used to fail once it reached
the &, fixed now.
FilterQueryString: fix parsing expression lists

The parser sometimes failed when reaching a=b&b=(c|d|e) - fixed.
FilterQueryString: fix handling encoded <> signs

Those signs are URL-encoded and therefore not "seen" before decoding
the "key" part when the sit in front of the = sign. Same goes for
standalone ones. Fixed.