This middleware adds support for grepping objects in-place using the GREP
method and the "e" query parameter. "e" was chosen go match grep(1). Other
grep parameters may be implemented later if needed.
It detects gzip and bzip2 files and decompresses them inline.
This is intended to allow backend tools to search log files.
Example:
GREP /sda/123/account/container/object?e=SEARCH HTTP/1.1
Change-Id: I569a72f4fc0f8ab85b90e8677f6daff0e28e8a79
73558d1412