(PDB-700) Allow changes to maxFrameSize in activemq

- maxFrameSize previously defaulted to 100 MB.  Now default is 200 MB with user
  configurability.
(PDB-577) Lower KahaDB MessageDatabase logging threshold.

- Previously, premature termination of PuppetDB import under specific ownership
conditions led to a residual KahaDB lock file that could prevent subsequent imports
from running with no obvious reason why.  This patch lowers the log threshold
for KahaDB MessageDataBase so affected users are informed.
(PDB-130) Fixes a nasty traceback exposed when users run import from command line with an invalid filename. A friendly message is now printed instead.
Merge pull request #989 from wkalt/ticket/master/pdb-700-max-framesize

(PDB-700) Allow changes to maxFrameSize in activemq
Merge pull request #990 from wkalt/ticket/master/pdb-130-no-file-on-import-message

(PDB-130) Replaces traceback exposed when puppetdb import is passed a missing file.
Merge pull request #991 from wkalt/ticket/master/pdb-577-KahaDB-lock-file-broker-failure

(PDB-577) Lower KahaDB MessageDatabase logging threshold.