Added Synapse-specific exception wrappers.
Changed thrown generic exceptions to the new ones.

Currently fails one test (integration_tests/integration/integration_test.py:test_evaulations) since the new feature has not been pushed to production yet.
Modified the unit/integration tests to use the new exceptions.
Changed description text for param contentSource.
Merge pull request #83 from kkdang/develop

Changed description text for param contentSource.
Merge pull request #75 from kaysoky/exceptionOverhaul

Added Synapse-specific exception wrappers.