1. Encapsulated into a few small functions the management of session-level

1. Encapsulated into a few small functions the management of session-level
information (currently just the transaction ID).

2. Fixed a bug in the treatment of the transaction ID that had caused us to
issue useless extra rollbacks whenever we did a commit or a rollback.

3. Further tinkered with comments.

M    Open-ILS/src/c-apps/oils_cstore.c

git-svn-id: svn://svn.open-ils.org/ILS/trunk@15668 dcc99617-32d9-48b4-a31d-7c20da2025e4