Make it easy to add custom target executions in the automatic
eclipse configuration generation, for example to call other
standard waf targets from other tools or with specific options.
When CDT is not included in the project (ie. we just have Python and/or Java) the current implementation would not create automatically a call to waf
for the build stage. This patch adds in such cases an external builder that automates the call to waf without the need to manually configure one.
Federico Pellegrin