Inspector: some items for "Lines" have no effects

Context: commit 2e40e6dfc (2013-04-30)

Description:
The Inspector controls for several elements of the "Lines" palette have no effects. In some cases, the new value is stored (and set into the Inspector when the element is selected again) but there is no visible change.

Generic line:

• "Colour" is stored but has no effect

Hairpin:

• "Visible" is stored but has no effect
• "Colour is stored but has no effect
• "OffsetX is stored but has no effect
• "Offset Y is stored but has no effect

8a (and similar):

• "Visible" only affects line, not text
• "Colour" is stored but has no effect
• "Type" has not effect

Pedal(s):

• "Colour" only affect text, not line

Trill (and similar):

• "Type" has no effect

Volta:

• "Visible" affects only line, not text
• "Colour" is stored but has no effect
• "Type" has no effect
Note:
For some types, like the generic line, this seems related to the fact that a TextLineSegment is set into the Inspector, but visual parameters are taken from the parent TextLine for display.