Added helper to see if a user has a binary available in their path. Also included associated tests.
Added a flag for doing MD5 verification.
Updated MD5_SUM_BINARY to specify a binary by name rather than being a boolean.
Added verification of md5 hash verification tool's existence, as well as exiting if a verification tool is specified but not found.
Replaced SHA1 hashes with MD5 hashes for boost and bullet.
Added method for md5 verification, as well as its associated test method.
Removed debugging exit.
Added check for md5 hashing being disabled.
Added MD5 verification call for both boost and bullet.