Patch from Scott McKellar:

Patch from Scott McKellar:

1. Added the const qualifier in various places.

2. Eliminated some unnecessary calls to strlen(), where they were
used merely to determine whether a string was empty.

3. Ensured that all members of a new transport_message are
explicitly populated.

4. Plugged a memory leak in the case where strdup() fails.

5. Eliminated some unhelpful casts of malloc'd pointers.

6. Added some protective tests for NULL pointer parameters.

7. In several spots I replaced numeric literals with character
literals, both to make the code more readable and to avoid a needless
dependence on ASCII.

8. Rewrote the jid_get_resource function to avoid repeatedly
overwriting the same buffer.

git-svn-id: svn://svn.open-ils.org/OpenSRF/trunk@1194 9efc2488-bf62-4759-914b-345cdb29e865