Make not_before and not_after be integers.
Make not_before and not_after be integers.

I'm no longer storing the raw ASN1_TIME structures for later parsing, so
nuke everything related to that. This also means we can go back to returning
void for pe_parse_certificates.

ASN1_GetTimeT() is a cleaned up and slightly modified version from
http://stackoverflow.com/questions/10975542/asn1-time-conversion. It seems
to work well enough, but I suspect it will have some edge cases.

tdr130/yara,hillu/yara,rayyang2000/yara,smaudet/yara,mgoffin/yara,mgoffin/yara,MeteorAdminz/yara,foreni-packages/yara,MeteorAdminz/yara,hillu/yara,bmagistro/yara,kallanreed/yara,hillu/yara,pombredanne/yara,0x0mar/yara,digideskio/yara,cblichmann/yara,cblichmann/yara,VirusTotal/yara,rayyang2000/yara,frbapolkosnik/yara,Security513/yara,smaudet/yara,jpypi/yara,digideskio/yara,jshufelt/yara,mgoffin/yara,binsrc/yara,foreni-packages/yara,kallanreed/yara,wxsBSD/yara,wxsBSD/yara,plusvic/yara,beikezcs/yara,0x0mar/yara,pombredanne/yara,VirusTotal/yara,jpypi/yara,frbapolkosnik/yara,plusvic/yara,jshufelt/yara,Security513/yara,rednaga/yara,hillu/yara,rednaga/yara,pombredanne/yara,pombredanne/yara,tdr130/yara,frbapolkosnik/yara,tanium/yara,mgoffin/yara,smaudet/yara,beikezcs/yara,VirusTotal/yara,bmagistro/yara,0x0mar/yara,tanium/yara,neatsun/yara,digideskio/yara,kallanreed/yara,plusvic/yara,VirusTotal/yara,jshufelt/yara,plusvic/yara,digideskio/yara,wxsBSD/yara,0x0mar/yara,rednaga/yara,binsrc/yara,plusvic/yara,cblichmann/yara,wxsBSD/yara,neatsun/yara,bmagistro/yara,foreni-packages/yara,binsrc/yara,smaudet/yara,jpypi/yara,jshufelt/yara,rayyang2000/yara,msuvajac/yara,msuvajac/yara,neatsun/yara,cblichmann/yara,tanium/yara,msuvajac/yara,MeteorAdminz/yara,cblichmann/yara,Security513/yara,pombredanne/yara,frbapolkosnik/yara,wxsBSD/yara,hillu/yara,binsrc/yara,beikezcs/yara,tdr130/yara,VirusTotal/yara