Merge tag 'ios-maven-plugin-1.4.1' into develop

Create tag 1.4.1
Update version to 1.4.2-SNAPSHOT
If value for buildSetting is null, then buildSetting will not be added. This fixes the issue of the plugin inserting the string 'null
' when no value is passed.
Merge pull request #1 from rkedwards/develop

When no value is passed for a buildSetting, do not add the buildSetting.
Update version to 1.4.2
Merge branch 'release/1.4.2'