ACCUMULO-1637 Add tests for append/sync conf check

Added in a few tests, given a hadoop-1.0.4 dependency, that make sure we
fail when appropriate. Had to change the access control on the method in
TabletServer as well as throwing an exception instead of directly
calling System.exit() to make a more easily testable method.
Merge branch '1.5.1-SNAPSHOT'

Conflicts:
	server/src/main/java/org/apache/accumulo/server/tabletserver/TabletServer.java

ACCUMULO-1637 Expanding the tests to account for the VolumeManager
changes in 1.6