Merge pull request ChristianRiesen#33 from fkooman/fix-hash-algos

fix sha256 and sha512

Merge pull request ChristianRiesen#30 from fkooman/64b

fix 2038 support on 64 bit PHP >= 5.6.3

Merge pull request ChristianRiesen#29 from steffenweber/patch-1

Fix encoding of special characters in the label

Merge pull request ChristianRiesen#25 from fkooman/phpunit-update

support PHPUnit 5 and 6 as well

Merge pull request ChristianRiesen#18 from fkooman/random_compat

use paragonie/random_compat

Merge pull request ChristianRiesen#15 from mithodin/master

Add support for a time offset

Add image to options for google authenticator url

Thanks to @SamuelDauzon for the idea.

Merge pull request ChristianRiesen#12 from therealssj/hotp-counter

Add hotp counter window

Adjust composer require for phpunit

Add random_int with polyfill suggestions as default random generator

Not a BC. Just will use that first, if present. In PHP7 it's already part of the core, and the polyfill can be installed to take care of the rest. Always will fall back to the current methods. Fixes ChristianRiesen#8.

Thanks to @inanimatt for the suggestion.