We no longer `pollute' the namespace of possible header file names;
instead we move `ft2build.h' up by one level so that it gets
installed in the default include directory (e.g.,
/usr/local/include).  After this commit, only `ft2build.h' stays in
the compiler's include path.

No visible changes for the user who follows the standard FreeType
header inclusion rules.

* include/*: Move to ...
* include/freetype2/*: This directory, except `ft2build.h'.

* CMakeLists.txt (PUBLIC_HEADERS, PUBLIC_CONFIG_HEADERS,
PRIVATE_HEADERS), Jamfile (HDRMACRO, RefDoc), autogen.sh: Updated.

* builds/amiga/include/config/ftconfig.h, builds/freetype.mk
(PUBLIC_DIR), builds/symbian/bld.inf, builds/toplevel.mk (work),
builds/unix/install.mk (install, uninstall),
builds/unix/freetype2.in: Updated.

* builds/unix/freetype-config.in: Updated.
Emit -I directory only if it is not `/usr/include'.

* builds/wince/*, builds/windows/*: Updated.

* devel/ft2build.h, include/ft2build.h: Updated.

* include/freetype2/config/ftheader.h,
include/freetype2/internal/ftserv.h,
include/freetype2/internal/internal.h: Update all header file
macros.

* src/tools/chktrcmp.py (TRACE_DEF_FILES): Updated.

* docs/*: Updated.