ant tasks: Major rewrite of the ant tasks, in support of simplifying the SDK build.

* Bring some consistency to the nameing of the classes, based on the name of
  the underlying ceylon tool subcommand they execute.
* Support the use of <moduleset> and <reposet> which can be declared at the
  top level and referred to in a task via a 'refid'
* Use an 'antlib.xml' descriptor so that tasks are now declared using

    <typedef
        resource="com/redhat/ceylon/ant/antlib.xml"
        classpathref="ant-tasks"/>

  Rather than the old <taskdef>. This has the effect that <ceylonc> is now
  known as <ceylom-compile> etc.
* Print deprecation warnings when old-style usage is detected.
* Use a common base class (CeylonAntTask) for tasks which wrap invocations
  of ceylon tools.
* Get rid of ModuleAndVersion, and just use Module (which may have a verion
  optionally). This represents a small loss of type safety (but who care because
  this stuff isn't supposed to be a Java API which people actually use), but
  means we can have a sane Module.equals() which works properly for the
  ModuleSet
ant tasks: Fix the tests
Delete old tests of the ceylonc, ceylond and (old) ceylon **scripts**, which no longer exist
Mark test for #929 as failing
Fixes for the way ceylon-sdk is now laid out
Add support for a <javacoption> subelement to <ceylon-compile> for passing options to javac via --javac=... options to ceylon compile
ant tasks: Correct copyright comment headers in the ant tasks, keeping the ASL 2 license inherited from the Apache ant javac task in those tasks which are substantially related to it, but adding the project-default GPL2+classpath exception to those files which lacked a header before
ceylondoc: remove workaround for #877
Add copyright comment headers to java/ceylon files lacking them
and fix two tests broken by the correction of copyright headers.
Fix problem with classes satisfying Sequence exposed by the renaming of the SequenceImpl test done are part of the copyright headers fix
ceylondoc #927: fix bug in loading and sorting inherited members
InvocationBuilder: move the call to compute() from the factory methods of InvocationBuilder to the build() method
InvocationBuilder: Move the addition of implicit arguments (for array(), arrayOfSome() and arrayOfNone()) outside makeInvocation()
InvocationBuilder: We no longer have arrayOfSome() or arrayOfNone(), so we don't need to worry about prepending implicit arguments for them
InvocationBuilder: Transform the arguments *after* we've transformed the primary. For the NamedArgumentInvocationBuilder this is complicated by the fact that the vars have to be built before we transform the primary (because the first of those vars is the transformed primary\!), so we split up the populating of the vars from the appending of args
InvocationBuilder: Rename some methods
InvocationBuilder: Move some code messin' with the transformed primary from transformInvocation() to transformPrimary() where is belongs
InvocationBuilder: Move some mode code messin' with the transformed primary from transformInvocation() to transformPrimary() where is belongs
ErrorCollector: Minor
InvocationBuilder: Minor tidyup/inline