Added URL toggle function. Does NOT currently work with redis Session driver.

Signed-off-by: Sebastian Klaus <sebastian@klaus.com.au>
Added urlToggle documentation to README, corrected wrong inline comment in config.php

Signed-off-by: Sebastian Klaus <sebastian@klaus.com.au>
Thanks to ericmagnuson, the redis issue seems to be fixed.

https://github.com/juy/profiler/issues/43#issuecomment-25311645
Signed-off-by: Sebastian Klaus <sebastian@klaus.com.au>
Added some inline comments, amended README with more urlToggle details

Signed-off-by: Sebastian Klaus <sebastian.klaus@aegiscare.com.au>