Avoid passing size = -1 to PutObject API by requiring content-length
header in POST request (as AWS S3 does) and in Upload web handler.
Post handler is modified to completely store multipart file to know
its size before sending it to PutObject().
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.
This is written so that to simplify our handler code
and provide a way to only update metadata instead of
the data when source and destination in CopyObject
request are same.
Fixes#3316
These messages based on our prep stage during XL
and prints more informative message regarding
drive information.
This change also does a much needed refactoring.
