Print the Jedi version when REPL completion is used

This also makes debugging easier, because people see which completion
they're actually using.
Merge pull request #406 from davidhalter/repl_info

Print the Jedi version when REPL completion is used
static analysis prototype decription
fix virtualenv support
dive further into following imports, etc
update AUTHORS
small fixes to the analysis.Error class.
introduce a NestedImportModule class
fixed NestedImportModule
Merge branch 'dev' into linter
improved star import support preparation
star imports now have their own class, which will be important for AttributeError detection
Merge branch 'dev' into linter
removed a few debug things.
ImportError detection
testing structure for static analysis.
improved static analysis test base
static analysis import tests
more import-error detection tests
add tests for attribute errors