fixing hexdec on a 16 char hex number, which could actually exceed INT64

[dragoscirjan]

On a 16 'digits' hex chunck, i.e. bea15bfc5e308b1a, hexdec method can trigger erros, because the converted number could exceed PHP integer side.

A solution would be to create a _hexdec method using php-bc or php-gpm to convert the chunk to a decimal number, then convert the number to a 64 bit signed INT number and parse it with intval.

This is my approach, it's not the best, so hoping you guys will refine it further :)

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[dragoscirjan]

Need to fix some things before getting back with this PR.

[chingor13]

Thanks for submitting this!

[dragoscirjan]

Hi @chingor13,
Please see code changes for the suggestions you have made. I think this is the best form this could be done, for now.

[chingor13]

Thank you! The refactoring looks good so far. Just added a few smallish things.

[chingor13]

I don't think this interface is needed. There's only one implementation and its internal (or probably should be) until the need arises for a separate implementation.

[chingor13]

Please fill this out.

[chingor13]

LGTM. Thanks!

[un000]

@chingor13 could you make a release for this PR?