add doxygen infrastructure
remove boost-build submodule and add as explicit dependency
Merged
add information to the README
update ycm files for new directory structure
Setters for the simple members of the Sam API

only those whose data can be accessed independently inside the bam1_t
and bam_core_t structs. Basically the ones with fixed length.

* add simple members for alignment fields
* add simple flags
* add tests to all functions

this closes #13
Reduce code duplication in Sam API

make Sam inherit from both SamHeader and SamBody to avoid the
duplication of code and simplify writer and all other APIs.

This closes issue #16
Merged from origin