Support migrating merged GConf trees.

Check for and parse a ~/.gconf/%gconf-tree.xml file during migration.
This is mainly for Debian, which I think accidentally merged some users'
GConf trees at some point.

This also adds a command-line program (evolution-scan-gconf-tree-xml),
which parses an arbitrary %gconf-tree.xml file as a recovery measure.

(cherry picked from commit fd3ad46d19a02c4ea73117c9ebee7913ca388890)
Bug 710989 - Replace most uses of strcpy()

Because strcpy() can overwrite its buffer.  As with the previous
replacement of sprintf(), some of these could probably be replaced by
g_strdup(), but there could be some performance impact.

(cherry picked from commit 61bf9fb860ecb4c6ace37cf3414d68d298ec26cf)