add Symfony Process dependency
make archiver and storer parameters optional for BackupProcedure class
add basic native PHP usage to README
more native PHP instructions
improve documentation formatting
another swing at documentation formatting
update docs
another round on the docs
more doc formatting
Merge branch 'master' of github.com:ShawnMcCool/database-backup into docblocks

Signed-off-by: Dries Vints <dries.vints@gmail.com>

Conflicts:
	src/McCool/DatabaseBackup/BackupProcedure.php