Generalize proto_library.{h,cc} to translate_and_compile.{h,cc} so
that it can be used for both protobuf and rpcz.
Remove stray #include
Update testdata to use proto_library plugin.
Fix bug where "-I" flag causes next flag to become ignored as a bogus
include directory.  E.g., "-I -I." adds "-I." as a directory to search.
Meanwhile, "." does not get added.
Update Makefile to incorporate -I fix.
Add support for ephemeral_cc_sources in cc_library and cc_binary
rules.  An ephemeral source Source.c is re-compiled whenever a
cc_binary would link in Source.o.  This is useful for code that prints
a build timestamp.
Example for ephemeral_cc_sources
Use mkdir -p in case the dir has yet to be created.
Merge pull request #10 from vandevoorde/master

Supporting rpcz proto libraries