Add rest case for rhbz#1014301
Add testcase for rhbz#1012980
[artifact] Improve error messages for from_mvn_str
Modify testcase for #1014301

We expect colons in artifact definitions at all times, but let's check for more
descriptive error message
mvn_artifact: improve error messages
Add test case for rhbz#1012982
Cleanup pom_macros_test

Now it works with proper paths instead of relying on being run from current
directory
mvn_package: assume __default when package name is not provided

From now on mvn_package will by default set artifact to be installed into main
package (__default) if subpackage name is not provided on commandline
man: update mvn_package __default use
Simplify pom.properties injection
Do not duplicate directory entry if it already exists
Inject classifiers and extensions into artifacts