Fixing test failures resulting from Java 7 switch.  Failures were due to a bug in the SQLJoin.compareTo() implementation that only started showing up when the sequence of calls to compareTo changed.
The implementation was asymmetric in cases where neither this nor other have a defined joinOrderKey.  If two SQLJoin objects with INNER_JOIN were compared, for example, compareTo(x,y)==-1, and compareTo(y,x)==-1.
There was also a code path that allowed an innerJoin and an outerJoin to be compared as 0.  4 tests had expected results based on this incorrect comparison.

Note that there is still the possibility of tests breaking due to indeterminate ordering when .compareTo() returns 0.  It could be worth adding further checks against SqlJoin fields to better lock in a fixed ordering.
Merge pull request #15 from mkambol/compareTo

Fixing test failures resulting from Java 7 switch.  Failures were due to...