kmx git

Reorganize source to make things easier to find

- Move all libjpeg documentation, except for README.ijg, into the doc/
  subdirectory.

- Move the TurboJPEG C API documentation from doc/html/ into
  doc/turbojpeg/.

- Move all C source code and headers into a src/ subdirectory.

- Move turbojpeg-jni.c into the java/ subdirectory.

Referring to #226, there is no ideal solution to this problem.  A
semantically ideal solution would have involved placing all source code,
including the SIMD and Java source code, under src/ (or perhaps placing
C library source code under lib/ and C test program source code under
test/), all header files under include/, and all documentation under
doc/.  However:

- To me it makes more sense to have separate top-level directories for
  each language, since the SIMD extensions and the Java API are
  technically optional features.  src/ now contains only the code that
  is relevant to the core C API libraries and associated programs.
- I didn't want to bury the java/ and simd/ directories or add a level
  of depth to them, since both directories already contain source code
  that is 3-4 levels deep.
- I would prefer not to separate the header files from the C source
  code, because:
  1. It would be disruptive.  libjpeg and libjpeg-turbo have
     historically placed C source code and headers in the same
     directory, and people who are familiar with both projects (self
     included) are used to looking for the headers in the same directory
     as the C source code.
  2. In terms of how the headers are used internally in libjpeg-turbo,
     the distinction between public and private headers is a bit fuzzy.
- It didn't make sense to separate the test source code from the library
  source code, since there is not a clear distinction in some cases.
  (For instance, the IJG image I/O functions are used by cjpeg and djpeg
  as well as by the TurboJPEG API.)

This solution is minimally disruptive, since it keeps all C source code
and headers together and keeps java/ and simd/ as top-level directories.
It is a bit awkward, because java/ and simd/ technically contain source
code, even though they are not under src/.  However, other solutions
would have been more awkward for different reasons.

Closes #226
kc3-lang/libjpeg-turbo/doc/turbojpeg/search/mag_sel.svg

Commit

doc/turbojpeg/search/mag_sel.svg
