Optimize signed operations

• Optimize signed multiplication
• Optimize signed division
• Add library interface usage examples
• Update readme

Optimize multiplication/division algorithms

-Change internal routines interface
-Tune multiplication/division calls
-Refactor

v1.1

Add standard stream input/output

• implement stream input/output operators
• refactor
• fix GCC specific overloads
• minor fixes

v1.0

v1.0

The first release of the library!