Don't return ERROR_WRONG_ARGUMENTS in "hash" module's functions.
Don't return ERROR_WRONG_ARGUMENTS in "hash" module's functions.

Some functions in "hash" module (like sha256, sha1, md5) were returning ERROR_WRONG_ARGUMENTS upon receiving negative offsets or lengths. In those cases a more appropriate behaviour is returning an UNDEFINED value, as ERROR_WRONG_ARGUMENTS makes YARA abort the scanning.

pombredanne/yara,wxsBSD/yara,pombredanne/yara,plusvic/yara,plusvic/yara,wxsBSD/yara,cblichmann/yara,VirusTotal/yara,hillu/yara,cblichmann/yara,pombredanne/yara,wxsBSD/yara,pombredanne/yara,hillu/yara,hillu/yara,cblichmann/yara,VirusTotal/yara,cblichmann/yara,cblichmann/yara,hillu/yara,plusvic/yara,plusvic/yara,VirusTotal/yara,pombredanne/yara,wxsBSD/yara,wxsBSD/yara,VirusTotal/yara,VirusTotal/yara,plusvic/yara,hillu/yara