Made <cpr.h> include <cpr/unsafe.h> if CPR_UNSAFE is defined.
Ensured that <cpr/unsafe.h> defines CPR_UNSAFE if not yet defined.
Defined the experimental <cpr/generic.h> header file.
Ensured that Git ignores test/*.{log,trs} files created by `make check`.
Reworded the CPR_UNSAFE warning with stronger language.
Expanded the C++11 cross-reference with footnotes and more sections.
Defined the CPR_*_T preprocessor symbols for use in <cpr/generic.h>.
Added an Emplacement Operations section to the Design Notes chapter.
Imported robots.txt and favicon.ico file placeholders.
Updated the DOAP file to add the project description and fix FOAF links.