Update protobuf to 2.5.0.
Use the maven plugin.
Do not rely on correct version of protoc being in path. Instead assume source checkout relative to build area.
Release 1.9.1
Bump version to 1.9.2
j should be J
Make the Index the TreeLink, not the IndexDef, which is more or more deprecated.
Slight tweak to directory name exclusion.
This allows the build area to have source as part of its name (though not -sources).
merge nathanlws: Bump version 1.9.2

Merge pull request #985 from nathanlws/sql-layer/bump-version-1.9.2
https://github.com/FoundationDB/sql-layer/pull/985
merge MMcM: Slight tweak to directory name exclusion.

Merge pull request #986 from MMcM/sql-layer/fdbsqllayer-jar-match
https://github.com/FoundationDB/sql-layer/pull/986
merge MMcM: Make the Index the TreeLink, not the IndexDef

Merge pull request #987 from MMcM/sql-layer/less-index-def
https://github.com/FoundationDB/sql-layer/pull/987
New exception name
merge nathanlws: Fix typo in pkg section of build_packages

Merge pull request #988 from nathanlws/sql-layer/pkg-ln-typo
https://github.com/FoundationDB/sql-layer/pull/988
merge MMcM: Update protobuf to 2.5.0.

Merge pull request #989 from MMcM/sql-layer/protobuf-250
https://github.com/FoundationDB/sql-layer/pull/989
merge nathanlws: MT was expecting old exception name

Merge pull request #990 from nathanlws/sql-layer/fix-mt-expected
https://github.com/FoundationDB/sql-layer/pull/990