Use pkgconfig about python-chardet

[jayvdb]

peterjc/backports.lzma#11 and python-lz4/python-lz4#76 use package pkgconfig to simplify this.

[Joungkyun]

I tested it as follows:

    import pkgconfig

    pkg = pkgconfig.parse ('chardet')
    libdir.append (pkg['library_dirs'])
    incdir.append (pkg['include_dirs'])

However, in the test, an error occurs as follows:

gcc -pthread -fno-strict-aliasing -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -D_GNU_SOURCE -fPIC -fwrapv -DNDEBUG -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector-strong --param=ssp-buffer-size=4 -grecord-gcc-switches -m64 -mtune=generic -D_GNU_SOURCE -fPIC -fwrapv -fPIC -I[u'/usr/include/chardet'] -I/usr/include/python2.7 -c src/chardet.c -o build/temp.linux-x86_64-2.7/src/chardet.o
src/chardet.c:18:21: fatal error: chardet.h: can not found
 #include <chardet.h>
                     ^
compilation terminated.
error: command 'gcc' failed with exit status 1

When using the PKGConfig module, additional parsing is more required, and the code complexity seems to be higher.

-I[u'/usr/include/chardet'] -> -I/usr/include/chardet

[jayvdb]

That is because each library can have more than one directory for includes and libs. No parsing is needed.
Use

    libdir += pkg['library_dirs'])
    incdir += pkg['include_dirs'])

[Joungkyun]

That is because each library can have more than one directory for includes and libs. No parsing is needed.
Use

    libdir += pkg['library_dirs'])
    incdir += pkg['include_dirs'])

sound good. thanks