Test case code for BYTEMAN-236

n.b. this test is not run from the test suite as the related issue has
not yet been resolved
merge in James Livingston's patch for BYTEMAN-238
Merge branch 'master' of github.com:bytemanproject/byteman

Pulling in Amos's fixes for BYTEMAN-190
moved script checker code into common package and renamed maven checker jar
oops, missed this change at the last commit
completed refactoring of check code fixes for BYTEMAN-190

Added ability to store info messages to RuleCheckResult

Tweaked class RuleCheck so that it will stream messages to a
printstream as well as collect them in theits RuleCheckResult

Modified TestScript class -- the one used by bmcheck -- so that it
delegates to class RuleCheck

Replaced RuleCheck.isOk() with RuleCheck.hasErrors() to be in keeping
with hasWarnings() and modified TestRuleCheck and RuleCheckMojo to use
this method to test the result.

Made TestRuleCheck print warnings as well as errors so we see at build
time which rules in the test rule set have warnigns against them.