Changed check for $cygwin to existence of /usr/bin/cygpath, fixes CORE-620.
Changed check for $cygwin to existence of /usr/bin/cygpath, fixes CORE-620.

git-svn-id: a91d99a4c51940524e539abe295d6ea473345dd2@1451 e6edf6fb-f266-4316-afb4-e53d95876a76

liquibase/BACKUP_FROM_SVN,liquibase/BACKUP_FROM_SVN,liquibase/BACKUP_FROM_SVN