Add option to debug spirit parser
Add utf8 test-case
Fix utf-8 parsing

Accept non-ascii characters in double_quoted rule.
This will make json parser utf-8 friendly.
Required at least cmake 2.8.11

CMake function `target_compile_definitions` introduced since 2.8.11:

http://www.cmake.org/cmake/help/v2.8.11/cmake.html#command:target_compile_definitions
Merge pull request #10 from ruslo/debug.option

Provides a config-time switch to optionally produce Spirit-specific debug information in Debug builds
Merge pull request #9 from ruslo/utf8.friendly

Utf8.friendly