Merge pull request #60 from gordon/master

use $(AR) variable instead of ar
clean up err object
accept GT_SEED environment variable
fix gtruby tests with cairo=no
use fixed seed in test suite
add documentation for GT_SEED
remove bbm-macros dependency for manuals
Merge pull request #65 from satta/bbm

remove bbm-macros dependency for manuals
Merge pull request #64 from satta/seed

Use fixed seeds in test suite