[Persistence] Derby-friendly SQL for search

Modify SQL statements for search functionality
such that syntax errors are not encountered
when using Derby, as recorded in nasa/mct#125.
Specifically, remove redundant semicolon, and
use javax.persistence.Query API to set maximum
results, instead of using limit keyword.
[Persistence] Test search

Test search method in persistence (previously
this was not covered by tests due to Derby
incompatible SQL syntax.)
[Persistence] Allow max search results configuration

Add a property to persistence.properties to permit
the maximum number of displayable search results to
be specified. Remove misleading key-vale pair from
mct.properties (which implies the ability to set
same, but in fact does nothing.)

Resolves nasa/mct#268.
Merge pull request #270 from VWoeltjen/mct125

[Persistence] Permit Search when using Derby