Merge pull request #143 from dustyleary/master

add_boost_library(system), needed for WITH_SYSTEM_BOOST on Mac
Added UrlDirectory function

primary used to get the current directory from the URL of the page.which can be used in case of async post or get to another page in the same directory.
Added UrlDirectory function

primary used to get the current directory from the URL of the page.which can be used in case of async post or get to another page in the same directory.
Merge pull request #144 from hrhrprasath/master

Added UrlDirectory method
add_boost_library(date_time) and add_boost_library(regex)