Tests for bug 8099 - XMLHttpRequest lowercase post requests broken.

get(""): GET(null bytes), Content-Type: null
post(""): POST(0 bytes), Content-Type: application/xml
DoIt(""): DoIt(0 bytes), Content-Type: application/xml
get(""): GET(null bytes), Content-Type: null
post(""): POST(0 bytes), Content-Type: application/xml
DoIt(""): DoIt(0 bytes), Content-Type: application/xml