change vertexFor to findOrCreateVertexFor

- vertexFor method has a side effect of creating new vertex if there
  is no vertex with given data
- findOrCreateVertexFor explains this intent more clearly
added notes to setup test env [skip ci]
keep the bin/*bat files in line with unix scripts - fix #1151
Fix test_load.rb

This was recently enabled in 4b6dfbc, probably accidentally.  Happy
accident though: it's working in 1.9 now once we re-add the
requireTest-1.0.jar, so that's one less FIXME.
Remove failing ffi-dependent test

With ffi being removed in 1ca75b2, this test is no longer valid.
Fixes #1154. Pathname.new(Dir.new('dir_name')) raises a TypeError (Dir missing to_path)
only pack the required jars
build gem with SNAPSHOT version
Merge branch 'jruby-1_7' of jruby.org:jruby into jruby-1_7
added a note on clean builds [skip ci]
Fixes #1163. File.expand_path should fail if ENV['HOME'] isn't an absolute path
Remove Kernel.gsub_bang as that was removed in 1.9
Remove 1.8 compatiblity methods from Kernel
Remove 1.9 compatibility flags from Kernel
Remove unused 2.0 compatibility flag from Kernel
Fixes #305. JRuby fails to parse a block under certain circumstances.
Merge
Merge pull request #1168 from Sinjo/deversion_kernel_take_two

Finish deversioning RubyKernel.java
Remove Kernel.gsub_bang as that was removed in 1.9
Remove 1.8 compatiblity methods from Kernel