Fix broken HTML generated from index.md.

Closes: CAMKES-297
Merge pull request #6 from mfernandez/master

Fix broken HTML generated from index.md.
Fix more broken HTML generated from index.md
Add to CAMKES_FLAGS instead of overwriting
Merge pull request #7 from adanis/camkes_flags

Add to CAMKES_FLAGS instead of overwriting
Use new muslc port. Change _start to _camkes_start that creates an environment compatible for calling to the regular _start
Correctly use CPPFLAGS and invoke CC instead of ASM to match the kind of flags we pass
Add CXX files to build system
Changes to libsel4debug include namespace
Pass a tls_init function to a threads _start routine so that TLS can be initialized
with the C library before execution gets to component_main
Added DMA support.