[trunk] Backw. comp.: lyrics underscores from 1.0 are sometime corrupted

Setup: trunk rev. 4219 both under Win XP (Qt lib 4.7.0) and Ubuntu (Qt lib 4.6.2)

Step: open with trunk the attached sample score created with 1.0

Result: some of the syllable extension underscores are corrupted (going back rather than forward).

Note: this happens because in function Lyrics::read() (file lyrics.cpp), 1.0 tag <endTick> might be read before tag <tick> and being converted from absolute to relative tick position using a wrong score()->curTick value.

The attached patch fixes it, by waiting the end of the <Lyrics> tag before converting absolute <endTick> value to relative Lyrics::_ticks value.

Tested with several 1.0 scores.