Melisma line length ignores chord position

Ubuntu 14.04, GIT commit: 74ba9fe

There are a number of aspects to this, already fixed in code that is currently commented out as a result of the manual merge of two conflicting commits. The line ends at the proper segment in all cases, but the exact length of the line relative to that position is off in a number of cases:

- if you apply a horizontal offset to the chord (either direction), the line does not adjust
- if the chord is offset due to a multi-voice collision
- if the chord has ledger lines, they are factored in, whereas they shouldn't be
- if there are mutliple voices different widths (whole versus quarter) and we guess wrong about which voice this melisma should be positioned relative to

These were the cases my code was designed to fix. But indeed, there was a conflict with Miwarre's change involving hyphen length. I will study this and submit my own merged version for review.