started work on FileCollection
added example html/css to gitignore
updated plugin description line
updated codenarc ruleset
slight update of buildscript (introduced gradle.properties)
removed strange import
updated path
added FileCollector class - to keep the plugin classes free of file handling trivia
it's a Specification, not a Test :-)
added  @Unroll to specification
first (trivial) base-cases of validateInputs handled (failures if no files are given)
more faulty configurations specified
FileCollector now handles files in the configured directory
Specification for illegal or absurd configurations
collectFiles now works recursively - at least in simple cases...

restricted to FILES
Specification for nested directory structures with scattered html- and non-html files all around
added a specific Exception type to communicate misconfigurations
enhanced Misconfiguration exception
updated readme.adoc
reordered some statements in build.gradle