set jar manifest with main class and dependencies

The Jar was missing a manifest which denoted the location of the main
class and class paths of its dependencies. Now it is more convenient to
execute it from a shell
allow compiling whole directories from commandline

The first command line option has been extended to accept a directory.
All .java files in this directory and all subdirectories recursively are
compiled. The directory structure of the input directory is preserved
for the generated AS3 files.
remove hardcoded forced import of dictionary
fix nullpointer exception in AS3MutationVisitor
A nullpointer exception was thrown  when no import was declared but forced imports were specified
fix array initialization on declaration

An array declaration with initialization was compiled to someArray:Array
= 1,2,3,4;. Added the missing braces.
fix for each loop

for each loops in as3 are written with "for each"
Merge pull request #1 from westnordost/master

Enhanced commandline usage and some small fixes (via westnordost)