This commit adds the IntelliJ ipr extension to .gitignore. These project
files are created when running the Maven goal idea:idea.

reverted a few things that were not necessary
* semicolon change - coming in another PR
* .gitignore change - no longer using derby

Code cleanup
* test scoped hsqldb
* removed derby artifacts and references
* setting driver class is not necessary
* cleaned up unused objects in delete
* now running cleanup on client
* removed old assert(true) stub

Had to fix the semicolon issue for Derby.
Ended up switching to HSQLDB becuase Derby does not support LIMIT.

Fixes #451

* set .gitignore to standard eclipse
* update versions of Accumulo to 1.4.4
* Pin slf4j binding to 1.5.8

Accumulo, Thrift, and YCSB all use different versions of slf4j, causing
runtime issues because everything is bundled together. Pin the version
to something in the middle that seems to work, even if it's not the
latest and greatest version.

I have fixed a bug in insert() and delete() methods.There are also
some cosmetic changes to readme and properties files.