Add test case for comment inside hex string.
Add test case for comment inside hex string.

Also move all comments-related tests to the test_comments function.

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