Make gmp functions return strvals each time
Merge remote-tracking branch 'upstream/master' into standardize_gmp
Return int or string for most of the GMP functions, instead of a resource. Added tests to never expect a resource to come from these functions.
See for tests...
Merge pull request #19 from afk11/standardize_gmp

Standardize gmp
Test coverage badge
Merge pull request #20 from Spomky/master

Test coverage badge
Makefile restored
Merge pull request #21 from Spomky/master

Makefile restored
Update README
Update README.md
Code design

* composer.json file:
    * Namespace for tests moved in a dedicated section
* README.md file:
    * HHVM badge added
* src/NumberTheory.php and test:
    * RootSquareException replaced by LogicException
* tests/unit/MathTest.php:
    * ` and ` replaced by ` && `
* src/* and tests/* files:
    * Code design reviewed to be compliant with PSR-1 and PSR-2

Bugs fixed
Merge pull request #24 from Spomky/master

Code design
Omit version from install instructions

Composer now installs the latest stable version available when omitted from command
Test case for dechex conversion & fix
Merge pull request #26 from aztech-digital/composer-instructions

Composer instructions
Fix hexDec tests

Tests were failing because of strict type checking (string vs int)
Remove empty test
Merge pull request #27 from aztech-digital/dechex

Test case for dechex conversion & fix