codegraph with readable path

Summary:
For diff analysis with codegraph to work, the path stored in must be relative to the project root,
         so that graph_code.marshall can be shared amoung different users.

Test Plan: make test

Reviewers: pad, pieter, mathieubaudet

Reviewed By: pad

CC: platform-diffs@lists

Differential Revision: https://phabricator.fb.com/D901334
* changes.txt: misc
* tests/php/parsing/generics_type_array.php: some rename
* lang_php/parsing/parser_php.mly: comments
pfff: support @ soft type annotation

Test Plan: unit test included

Reviewers: amenghra, pieter, glevi, jiaol, ashwin

Reviewed By: ashwin

CC: ashwin

Differential Revision: https://phabricator.fb.com/D902460

Task ID: 2630429
* lang_php/analyze/foundation/graph_code_php.ml: comment
* tests/php/codegraph/xhp_use.php:
* lang_php/analyze/foundation/graph_code_php.ml: better error on undefined
class constants that are actually undefined class
* h_program-lang/graph_code.ml: misc
* lang_php/analyze/foundation/graph_code_php.ml: fix comment
* lang_php/analyze/foundation/graph_code_php.mli: clean
* lang_php/analyze/foundation/graph_code_php.ml: estet
* tests/php/codegraph/pfff_test.exp: adjust
* lang_php/analyze/foundation/graph_code_php.ml:
* lang_php/analyze/foundation/graph_code_php.ml: use TodoNamespace
* lang_php/analyze/foundation/ast_php_simple.ml: tok_of_name
* lang_php/analyze/foundation/graph_code_php.ml: do not stop when namespace,
but print warning
Add program_of_program2 to the interface for Parse_java

Summary:
See title.

I need this for the java_clobberer, coming soonish.

Test Plan: make

Reviewers: pad, jiaol

Reviewed By: pad

Differential Revision: https://phabricator.fb.com/D902846
* changes.txt: misc
Merge branch 'master' of github.com:facebook/pfff