remove rdtsc and sleep-mode options for #16
Properly process IPv6 extension headers - copy from 4.0alpha1 for #16
depricate --enable-file-cache option for #16 and #17
merge 4.0alpha1 for #18 which is subtask of #16
Add error message reporting and general cleanup. Closes #18 which is subtask of #16
Merge pull request #20 from appneta/Enhancement_#18_4.0alpha1_merge

Enhancement #18 4.0alpha1 merge which also merges #16 and #17