Introduce a cache of the configuration

You may have noticed that running make is a little slow. Every time
that it is loaded, it will try to detect everything again. So,
instead, save the output and reload it the next time.

This is implemented by adding a rule that (re-)creates the
config.cache file, which is included by make. If the file doesn't
exist yet, make will first run the rule which creates it, then reload
itself.

You can also cause it to reconfigure by running "make configure".

Signed-off-by: Thiago Macieira <thiago@macieira.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/Rules.mk b/Rules.mk
index 59e73e13d..5374e060b 100644
--- a/Rules.mk
+++ b/Rules.mk
@@ -197,4 +197,7 @@ clean:
 		$(VERSION_FILE) qt-ui/*.moc qt-ui/ui_*.h
 	rm -rf share .dep
 
+confclean: clean
+	rm -f $(CONFIGFILE)
+
 -include $(DEPS)