Support Custom Timeout for Queries

Allow the use of bearer_token or bearer_token_file for MarathonSD authorization

Adding version to names of static files

Prevent deadlock in ZK TreeCache constructor by deferring the initial sync.

Fixes #2254

to prevent browsers using old files in local caches after an upgrade.

Expose buildQueryUrl, refactor dispatch to use

buildQueryUrl will allow users to execute queries over the range of an
existing graph.  This will be helpful to select data series they wish to
annotate the graph with, for example.

Fix fuzzy search lookup issues

notifier: Allow swapping out HTTP Doer

We need to be able to modify the HTTP POST in Weave Cortex to add
multitenancy information to a notification. Since we only really need a
special header in the end, the other option would be to just allow
passing in headers to the notifier. But swapping out the whole Doer is
more general and allows others to swap out the network-talky bits of the
notifier for their own use. Doing this via contexts here wouldn't work
well, due to the decoupled flow of data in the notifier.

There was no existing interface containing the ctxhttp.Post() or
ctxhttp.Do() methods, so I settled on just using Do() as a swappable
function directly (and with a more minimal signature than Post).

* Limit 'discarding sample' logs to 1 every 10s

* Include the vendored library

* Review feedback

Re-add multiple remote writers

Each remote write endpoint gets its own set of relabeling rules.

This is based on the (yet-to-be-merged)
https://github.com/prometheus/prometheus/pull/2419, which removes legacy
remote write implementations.

Replace AUTHORS.md by an updated MAINTAINERS.md

Add rickshawGraph property to the Graph object.

This allows further changes to be made to the graph, for example,
annotations.

Adding gauge for number of open head chunks.

Now incrementing numHeadChunks directly.

Fix kubernetes host:port relabel regex.

Fixes #1710

This change corrects a bug introduced by PR
https://github.com/prometheus/prometheus/pull/2427

The regex uses three groups: the hostname, an optional port, and the
prefered port from a kubernetes annotation.

Previously, the second group should have been ignored if a :port was not
present in the input. However, making the port group optional with the
"?" had the unintended side-effect of allowing the hostname regex "(.+)"
to match greedily, which included the ":port" patterns up to the ";"
separating the hostname from the kubernetes port annotation.

This change updates the regex for the hostname to match any non-":"
characters. This forces the regex to stop if a ":port" is present and
allow the second group to match the optional port.

Kubernetes port annotations - match addresses with or without declared ports

This change updates port relabeling for pod and service discovery so the
relabeling regex matches addresses with or without declared ports. As
well, this change uses a consistent style in the replacement pattern
for the two expressions.

Previously, for both services or pods that did not have declared ports, the
relabel config regex would fail to match:

    __meta_kubernetes_service_annotation_prometheus_io_port
    regex: (.+)(?::\d+);(\d+)

    __meta_kubernetes_pod_annotation_prometheus_io_port
    regex: (.+):(?:\d+);(\d+)

Both regexes expected a <host>:<port> pattern.

The new regex matches addresses with or without declared ports by making
the :<port> pattern optional.

    __meta_kubernetes_service_annotation_prometheus_io_port
    __meta_kubernetes_pod_annotation_prometheus_io_port
    regex: (.+)(?::\d+)?;(\d+)

vendoring: Do not ignore appengine build tags

Remove legacy remote storage implementations

For weird reasons, this excluded github.com/miekg/dns/udp_other.go
from vendoring.

This removes legacy support for specific remote storage systems in favor
of only offering the generic remote write protocol. An example bridge
application that translates from the generic protocol to each of those
legacy backends is still provided at:

documentation/examples/remote_storage/remote_storage_bridge

See also https://github.com/prometheus/prometheus/issues/10

The next step in the plan is to re-add support for multiple remote
storages.

discovery: Instead of looping over conf.Search, use NameList()