PretextGraph-0.0.9

Changes:

• removed the normalisation for repeat_density extension. The repeat density was normalised by the bin_size. But there are some bins with different sizes, which will make the repeat_density signal incorrect.
• removed the dependency of Wrapper by adding the SIMDExtensionWrapper.cpp inside of the project.
• change the function of stbsp_snprintf to snprintf to avoid segfault.
• update version number to 0.0.9