Look for config file under two well-known names w/o -c

[Thomas Lotze]

Currently, buildout looks for its configuration file under the name buildout.cfg unless a different name is specified as the -c command-line parameter.

This means that on the one hand, one wants to keep a version-controlled buildout.cfg so that developers who start working from a fresh check-out or machines such as continuous-integration servers have an easy time bootstrapping the buildout. On the other hand, this requires local customizations to go in a different file that needs to be specified by the -c option on each and every subsequent call to bin/buildout.

It would therefore be helpful if buildout looked for its configuration in two places by default (i.e. unless -c is specified). They might be either buildout.cfg and local.cfg, or base.cfg and buildout.cfg, the second extending the first in both cases. Then, the first of these files might be kept under version control and second be optional, ignored by VC and reserved for local customisations. buildout would have to look for the local file first and fall back to the base if no local configuration exists. The behaviour of the -c option should be completely unaffected.