Fix github issue #312:
Fix github issue #312:

- removed non-generic fields that cannot be normalized
- added normalized fields for username, uri's, useragent
- removed erroneous example (did not follow the mandatory fields rules...)

This is an effort to normalize fields so that alerting and correlation results are more consitent.
Please open github issues for discussion when adding new fields! These should generally be generic, often-used-by-all
fields

mpurzynski/MozDef,jeffbryner/MozDef,ameihm0912/MozDef,Phrozyn/MozDef,netantho/MozDef,ameihm0912/MozDef,mpurzynski/MozDef,mozilla/MozDef,jeffbryner/MozDef,netantho/MozDef,jeffbryner/MozDef,gdestuynder/MozDef,gdestuynder/MozDef,Phrozyn/MozDef,gdestuynder/MozDef,mozilla/MozDef,jeffbryner/MozDef,mpurzynski/MozDef,mozilla/MozDef,ameihm0912/MozDef,gdestuynder/MozDef,ameihm0912/MozDef,mpurzynski/MozDef,Phrozyn/MozDef,netantho/MozDef,netantho/MozDef,mozilla/MozDef,Phrozyn/MozDef