Fix bar line generated status when reading old scores

In old scores (1.x and transitional 2.0 scores, including templates and "My First Score"), regular bar lines are often needlessly stored in score files.

These bar lines are read back as non-generated, and may misbehave; for instance, may generate an extra 'courtesy' start-repeat at system end, if a start-repeat is added at the first measure of next system.

This fix normalizes bar line flags if, while reading them back, they are found to be normal.

Notes: only a few lines of code are changed in Measure::read() methods; the large number of affected files is due to fixing test files to remove the extra bar lines from the reference files.

Waiting for Travis response for a more precise check about test files.