Add Rules-Requires-Root field, and set it to "no".

Fix some issues reported by lintian

Fixes lintian: insecure-copyright-format-uri
See https://lintian.debian.org/tags/insecure-copyright-format-uri.html for more details.

Fixes lintian: vcs-field-uses-insecure-uri
See https://lintian.debian.org/tags/vcs-field-uses-insecure-uri.html for more details.

Fix up variable assignments

Add -fvisibility=hidden to DEB_CFLAGS_MAINT_APPEND so clang doesn't
export extraneous symbols.

This is specific to qnx.

build error with qnx6.5.0

../yajl-2.0.1/lib/libyajl_s.a(yajl_gen.c.obj): In function yajl_gen_double':
yajl_gen.c:(.text+0x5b9): undefined reference to_DclassBuilding C object example/CMakeFiles/parse_config.dir/parse_config.c.obj
'
yajl_gen.c:(.text+0x5cf): undefined reference to `_Dclass'
cc: /opt/qnx650/host/linux/x86/usr/bin/ntox86-ld error 1
make[2]: *** [reformatter/json_reformat] Error 1

any platform that links does not link libm while linking libstdc

http://community.qnx.com/sf/discussion/do/listPosts/projects.toolchain/discussion.core_development_tools.topc10811?_pagenum=2

In BUILDING.WIN32, the following line exists:

  nmake install

This doesn't work because the install targets never get built because of
the code:

  IF(NOT WIN32)
    INSTALL(...)
    ...
  ENDIF()

in several CMakeLists.txt files. There's no reason to disallow INSTALL
on Windows, even if most developers (who use devenv on its own) will
never use it.