V1.1.11 Space optimizations for asin & acos

The code for asin & acos was optimized to use less flash space.

For Linux users, the makefile was extended to allow creation of libraries for different AVR mcrocontrollers (MCU) named libfp64-%.a, where % stands for the selected MCU, e.g. libfp64-atmega328p.a for the Atmega 328p. libfp64.a will always link to the latest created library.