[boost] Line endings fixes

Hi, Please see the attached files. boost_endings1.patch just sets some of the cpp and other text files to have file endings consistent with the rest of the repository. boost_endings2.patch may be controversial as it does the same but for the svg files. Some of them are marked as text, others as binary. It's a real mess. Most of the svg files are generated from other sources so should probably be omitted from the repository and simply regenerated when docs are built. Came across these issues when checking out the modularised boost git repository. Regards, Vitaly