cleanup: Rename native source directories to match upstream names.

audio-sdl     --> mupen64plus-audio-sdl
core          --> mupen64plus-core
front-end     --> mupen64plus-ui-console
gles2glide64  --> mupen64plus-video-glide64mk2
gles2n64      --> mupen64plus-video-gln64 *
gles2rice     --> mupen64plus-video-rice
input-android --> mupen64plus-input-android *
rsp-hle       --> mupen64plus-rsp-hle

* Note that gles2n64 and input-android don't exist in the mupen64plus
organization. We will be adding them to the mupen64plus-ae organization
later.  In principle, we could one day transfer ownership to upstream,
but they're pretty rough or only apply to android, so we'll take care
of them for now.

This commit only changes the directory names, not the names of the
compiled libraries.  That will be a separate commit.
libs: Rename all native modules to match upstream names.
audio-sdl: Rename macro PAULSCODE -> ANDROID_EDITION.
ui-console: Rename macro PAULSCODE -> ANDROID_EDITION.
glide: Rename macro PAULSCODE -> ANDROID_EDITION.
rice: Rename macro PAULSCODE -> ANDROID_EDITION.
core/r4300: Surround Perfect Dark hack with ANDROID_EDITION guard.
doc: Fix URLs in javadoc.

URLs in the translated resources will be done later.
cleanup: Rename gles2n64 --> gln64 in comments and variables.

Changes to the resources (translations, keys) will be done later.
cleanup: Rename gles2glide64 --> glide64 in comments and variables.

Changes to the resources (translations, keys) will be done later.
cleanup: Rename gles2rice --> rice in comments and variables.

Changes to the resources (translations, keys) will be done later.
res: Updated translations.
res/assets: Change keynames gles2n64 --> gln64.
res/assets: Change keynames gles2glide64 --> glide64.
res/assets: Change keynames gles2rice --> rice.