change dir does not propagate to java runtime

[mkristian]

jruby -e 'Dir.chdir("..");p File.expand_path(".");p java.io.File.new("").absolute_path;p java.lang.System.get_property("user.dir")'

produces
"/home/christian/projects/active/maven/tesla-polyglot/tesla-polyglot-gems"
"/home/christian/projects/active/maven/tesla-polyglot/tesla-polyglot-gems/ruby-maven"
"/home/christian/projects/active/maven/tesla-polyglot/tesla-polyglot-gems/ruby-maven"

not sure how the java runtime 'knows' the pwd. one way is to set the user.dir system property:
``jruby -e 'Dir.chdir("..");java.lang.System.set_property("user.dir", File.expand_path("."));p java.io.File.new("").absolute_path;p java.lang.System.get_property("user.dir")'`

which does the trick at least for java.io.File

usually I am using jruby and ruby almost exchangable, i.e. ruby calls java and java calls ruby . . .

when looking at the jruby sources I am not sure whether the place to 'add' the system property fix is RubyDir.java or Ruby.java

[BanzaiMan]

Broke some test for Embedded.

[BanzaiMan]

Reverted the commit for now.

[BanzaiMan]

It's been pointed out that JVM may not like this. https://github.com/rubyspec/rubyspec/issues/248#issuecomment-23514353

[headius]

It sucks, but we should make our best effort to emulate chdir and deal with it at external integration points (anywhere that needs to see the chdir) rather than forcibly chdir the whole JVM (which will never work in typical server settings).

[mkristian]

yeah - something like: #2215