[tests] improve test-tempo coverage
[tests] use run_on_default_source in tempo
[tests] wrap long lines in test-tempo.c
[tests] run tempo until first analysis is done
[tests] run some tests in tempo if no arguments passed
[tests] check if tempo creation suceeded
tests/src/tempo/test-tempo.c: tempo back to only one output
src/tempo/tempo.c: fix for different samplerates
tests/src/{onset,tempo}/test-*.c: improve test programs
tests/src/tempo/: improve examples
tests/: move tests around