Add path for custom source repository of mvn dependencies

This commit adds two parameters making possible to specify a custom
remote repository from which are fetched dependent packages needed
for the build:
- maven.remote.repository.id to define the id of the remote repository
- maven.remote.repository.url to define the URL of the remote repository
Default values make process point to the central Maven repository, but
those values can be enforced using build.local.properties.