Implement eq and neq
Get rid of operator!=
Get rid of operator==
Merge pull request #9 from certik/eq

Use eq() and neq()
Create global zero and one Integers
Use global one and zero
Merge pull request #10 from certik/cache_ints

Cache ints
Add PACKAGE preprocessor definition.

Binutils 2.23 and newer require PACKAGE or PACKAGE_VERSION to be defined before
including bfd.h. This commit fixes the compilation errors reported on github
issue 4.
Merge pull request #11 from hazelnusse/config_h_fix

Add PACKAGE preprocessor definition.
Improve a comment and fix return type of as_int()
Add MIT license and AUTHORS file
Add .mailmap file
Travis: print full output on failure
Implement mul_expand()
Test it
Better printing
Implement simplifications in pow()
Fix a bug
Simplification
Implement missing branch in mul_expand_two