This makes the PBGitRevisionCell a bit nicer by retrieving all values
from the PBGitCommit object itself, and using another NSTextFieldCell to
draw the text.
This mean that PBGitGrapher now stores its information in the PBGitCommit's,
rather than in a custom grapher array. Also, because we don't need the
grapher to display refs anymore, the ref labels are also displayed when
using path limiting (for example, 'gitx -- Makefile').
This adds the "hasRef" boolean member in PBGitCellInfo which is set to true
if the specific commit has symbolic refs.
This is the first part in supporting labels just like gitk has. For now,
commits with refs are just displayed with a red circle.
Things that need to be done to support all refs:
* Make the NSDictionary in PBGitRepository contain arrays of refs,
not a single string
* Make PBGitGrapher store all refs of a commit in the PBGitCellInfo
* Figure out a nice way to display the labels in PBGitRevisionCell
This uses more Cocoa classes to draw the lines, making it easier to
understand and hopefully maintain.
Furthermore, we use less memory now, which is nice, but all the
dynamic arrays probably mean more CPU usage.
This takes care of most situations. However, we don't have enough space
in the upperMapping to display multiple lines. Therefore we need to
improve it later on.
Pieter de Bie