Fix error w/ lossless crop & libjpeg v7 emulation The JPEG_LIB_VERSION #ifdef in jtransform_adjust_parameters() was incorrect, which caused a "Bogus virtual array access" error when attempting to use the lossless crop feature. Introduced in c04bd3cc97f44fd9030de1e141754c8775d4e5a5. This also adds libjpeg v7 API/ABI emulation to the Travis CI tests.