Automatically infer original fragment length for truncated fragments …

…(Raw/Ethernet) (microsoft#28)

* infer original length

* update readme

* fix LSO packets

* fix comment

* cr feedback

* fix comment

* fix comments

misc tweaks (microsoft#16)

update gitignore to ignore release package (microsoft#13)

fix newline issue in readme (microsoft#10)

v1.0.0 (microsoft#6)

switch to semver (microsoft#5)