rdbms: various field name and style cleanups to Database

rdbms: various field name and style cleanups to Database

Rename Database::hasFlags() to sound less similar to getFlag()/setFlag().
The order of class fields is roughly:
* Objects and resources
* Configuration
* Mutable options that do not have to be kept in sync with the connection
* Session level state tracking (should be in sync with the connection)
* Transaction level state tracking (should be in sync with the connection)
* Results from or timestamp of the last time a certain event occurred

Change-Id: Ibdca2fefe7ed2c792344c5602b5191a950eed933