Add compile time GOROOT path to the list of prefix
of file paths to be removed.
Add webhandler function names to the slice that
stores function names to terminate logging.
Set GOPATH string to empty in build-constants.go
Check for both compile time GOPATH and default GOPATH
while trimming the file path in the stack trace.
Fixes#5741
This is a consolidation effort, avoiding usage
of naked strings in codebase. Whenever possible
use constants which can be repurposed elsewhere.
This also fixes `goconst ./...` reported issues.
