corrections in cpp promotion
added make_safe_literal
separated integers from other types
dropped example91
updated CMakeLists.txt and Jamfile.v2 accordingly
Turns out that these changes should also better position us to handle other underlying types - but we're not there yet.
Added example for composition with other types - example boost rational and boost multi precision
Added performance test using boost multi precision
Many other small corrections
a) made trap_exception work
b) updated manual and examples to show how to use library to eliminate runtime penalty
c) added in safe_literal
d) made corrections of various types
