Generalized profiling support

You can now capture any registered Go profile “profilename” by:
    POST /_profile/profilename
See the Go docs for pprof.Profile to see what profiles are available.
Standard ones are “heap”, “goroutine”, “threadcreate” and “block”.
The body of the request needs to be JSON with a “file” property
containing the path to write the profile to.
Admin API: User “all_channels” property includes role-inherited channels
Admin API: Extensions to _all_docs to get channel and access info

If you get /db/_all_docs?channels=true from the admin port, each row’s
“value” will include a “channels” property whose value is an array of
the channels that document is in.

With ?access=true, there’s an “access” property whose value is a
dictionary mapping user and role names to arrays of channels they’re
granted access to by this document. (Role names are prefixed with
“role:”.)

If you want to get info for only specific documents, you can either use
the startkey and endkey parameters, or POST with a JSON body that’s an
array of the document ID(s).
Compatibility improvement for _all_docs

Be more compatible with CouchDB:
* “total_rows” value is now the number of docs in the database, not
  the number of rows returned
* Added “update_seq” at top level; value is the latest db sequence #.
Log to console if Couchbase Server API calls take > 200ms

The messages look like “Go-Couchbase: Call to … took …”
CBLT-166:  only copy binary if it exists
CBL-4:     change order to test for sync problem

Change-Id: Icf3b87c23b24d407d1df1135cec5c3964b13b026
CBL-4: bail unless all binaries get made

Change-Id: I90508465906de9c8c92349f2fc50bc0bc5dedcd8
CBL-4: change order to test for sync problem

Change-Id: Ie2e75f7b48d10ccffd24b4af7468c2e9a5c95b8c
CBL-4:  windows binaries are .exe files

Change-Id: I876b3b8f625220408f81a890eb42ca4ea6ce8354
CBL-4:  windows binaries are .exe files

Change-Id: I4a6175e26a0eee417107772fc7c666a59649be83
CBL-4:  windows binaries are .exe files

Change-Id: Ia3f961ceb6f1adc13f6418cd3e6c6ec390c84ab9
CBLT-167:  Update README for Beta 2

Change-Id: Ib80788c4184c1d3a013c1315d4572a4cc6feb936
Bump VersionString to 0.91 (post-beta-2)
Added WebSocket support for the _changes feed

Use “?feed=websocket” to enable it. It’s comparable to continuous feed
except it upgrades the connection to WebSocket and sends groups of
changes as messages. Each message is a JSON array of change
dictionaries. An empty array means the server is currently waiting
for new changes; this can be used by the client to detect when
it’s “caught up”.
Fixes #143
Updated Walrus (minor enhancement)
add ability to create/update attachments using HTTP PUT

Allows for adding/updating attachments using simple curl command:
curl -XPUT .../db/doc_id/attachment_name?rev=document_rev_id --data-binary @attachment_file
fix #235 changes feeds
Fixed crash getting body of revision that’s in history but not stored

Fixes #237
make an admin handler to return the raw document content
admin api access to the deployed sync function code via config