Copyright-holder and year information is extracted from git log.
git history begins in 2005. So (C) from 1998..2005 is lost. Also some
(C) assignment of commits where the committer didn't use --author.
For every added Trackview/Mixerstrip, Ardour looks up GUI properties which
results in a total of 13 calls for the initial default items per track:
("height", "visible", "layer-display", "strip-width")
Since the tracks don't yet exist, the properties don't either.
Every lookup result in iterating over all all XMLNotes and for every
"Object". ->property ("id") and ->value () allocates memory.
Adding 64 tracks to an empty session results in 528293 string
allocations and deallocations in XMLNode::property() taking ~30%
of the track creation time.
This commit XMLnode's const method to prevent memory allocation
and caches a pointer to the XMLNode* to skip iterating over object
state.
