Add remove helper
Bump gradle wrapper to v1.9
Add Filterable annotation
Make defined field public
Fix Filterable transformation
Fix GenericSourceSetConventionTransformation
Bump wrapper to gradle v1.10
Move all transformations into macro source set

--HG--
rename : src/main/groovy/kotka/gradle/utils/Delay.groovy => src/macros/groovy/kotka/gradle/utils/Delay.groovy
rename : src/main/groovy/kotka/gradle/utils/Delayed.groovy => src/macros/groovy/kotka/gradle/utils/Delayed.groovy
rename : src/main/groovy/kotka/gradle/utils/DelayedTransformation.groovy => src/macros/groovy/kotka/gradle/utils/DelayedTransformation.groovy
Add dependency on spock extensions v0.1.4
Add SourceDirectoryTask
Add macros source set to the jar file
Fix source getter for SourceDirectorySet