[NaCl SDK Docs] Update PPAPI docs to use Chromesite-friendly URLs.

* Chromesite URLs must end in .html, unlike devsite.
* Non-doxygen docs are no longer versioned, so {{pepperversion}} should
  be removed from all URLs.
* Added FixPepperDocLinks() function to generate_docs.py. This will fix links
  for stable/beta/dev headers until this change makes it to stable.

BUG=none
R=sbc@chromium.org

Review URL: https://codereview.chromium.org/132283007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@247482 0039d316-1c4b-4281-b951-d872f2087c98

• native_client_sdk/doc_generated/pepper_beta/c/group___typedefs.html[diff]
• native_client_sdk/doc_generated/pepper_beta/c/struct_p_p_b___audio__1__1.html[diff]
• native_client_sdk/doc_generated/pepper_beta/c/struct_p_p_b___audio_config__1__1.html[diff]
• native_client_sdk/doc_generated/pepper_beta/cpp/classpp_1_1_audio.html[diff]
• native_client_sdk/doc_generated/pepper_beta/cpp/classpp_1_1_audio_config.html[diff]
• native_client_sdk/doc_generated/pepper_beta/cpp/classpp_1_1_image_data.html[diff]
• native_client_sdk/doc_generated/pepper_dev/c/group___typedefs.html[diff]
• native_client_sdk/doc_generated/pepper_dev/c/struct_p_p_b___audio__1__1.html[diff]
• native_client_sdk/doc_generated/pepper_dev/c/struct_p_p_b___audio_config__1__1.html[diff]
• native_client_sdk/doc_generated/pepper_dev/cpp/classpp_1_1_audio.html[diff]
• native_client_sdk/doc_generated/pepper_dev/cpp/classpp_1_1_audio_config.html[diff]
• native_client_sdk/doc_generated/pepper_dev/cpp/classpp_1_1_image_data.html[diff]
• native_client_sdk/doc_generated/pepper_stable/c/group___typedefs.html[diff]
• native_client_sdk/doc_generated/pepper_stable/c/struct_p_p_b___audio__1__1.html[diff]
• native_client_sdk/doc_generated/pepper_stable/c/struct_p_p_b___audio_config__1__1.html[diff]
• native_client_sdk/doc_generated/pepper_stable/cpp/classpp_1_1_audio.html[diff]
• native_client_sdk/doc_generated/pepper_stable/cpp/classpp_1_1_audio_config.html[diff]
• native_client_sdk/doc_generated/pepper_stable/cpp/classpp_1_1_image_data.html[diff]
• native_client_sdk/src/doc/Makefile[diff]
• native_client_sdk/src/doc/doxygen/generate_docs.py[diff]
• ppapi/api/ppb.idl[diff]
• ppapi/api/ppb_audio.idl[diff]
• ppapi/api/ppb_audio_config.idl[diff]
• ppapi/c/ppb.h[diff]
• ppapi/c/ppb_audio.h[diff]
• ppapi/c/ppb_audio_config.h[diff]
• ppapi/cpp/audio.h[diff]
• ppapi/cpp/audio_config.h[diff]
• ppapi/cpp/image_data.h[diff]
• ppapi/thunk/ppb_uma_private_thunk.cc[diff]