Feed keeps active subscription channels in a slice called 'f.sendCases'.
The Send method tracks the active cases in a local variable 'cases'
whose value is f.sendCases initially. 'cases' shrinks to a shorter
prefix of f.sendCases every time a send succeeds, moving the successful
case out of range of the active case list.

This can be confusing because the two slices share a backing array. Add
more comments to document what is going on. Also add a test for removing
a case that is in 'f.sentCases' but not 'cases'.

* all: get rid of error when create mdb

* core: clean up variables definition

* all: inline mdb definition

* eth/filter: check nil pointer when unsubscribe

* eth/filters, accounts, rpc: abort system if subscribe failed

* eth/filter: add crit log before exit

* eth/filter, event: minor fixes

* cmd: various golint fixes

* cmd: update to pr change request

* cmd: update to pr change request

Peer.run was discarding the reason for disconnection sent to the disc
channel by Disconnect.

* whisper/mailserver: pass init error to the caller

* whisper/mailserver: add returns to fmt.Errorf

* whisper/mailserver: check err in mailserver init test

* signer/*: golint fixes

Specifically naming and comment formatting for documentation

* signer/*: fixed naming error crashing build

* signer/*: corrected error

* signer/core: fix tiny error whitespace

* signer/rules: fix test refactor

* eth/*:golint updates for this or self warning

* eth/*: golint updates for this or self warning, pr updated per feedback

* event/*: golint updates for this or self warning

* event/*: golint updates for this or self warning, pr updated per feedback

* metrics/*: golint updates for this or self warning

* metrics/*: golint updates for this or self warning, updated pr from feedback

* rpc/*: golint error with context as last parameter

* Update json.go

clef: documentation about setup

build: Add ldflags "-s -w" when building aar

Smaller size on mobile is always good.
Might also solve our maven central upload problem

cmd/evm: use block number from genesis

core: ensure local transactions aren't discarded as underpriced