Check existence of $HELM_HOME/plugins before installing plugin

Adds alias for dependencies

fix(docs): Remove "no nested globals allowed"

Add check to stop helm 'waiting' for external services to become ready

Remove incorrect statements in charts.md about nested globals not being allowed.

Fixes https://github.com/kubernetes/helm/issues/2488

Errors out if install/upgrade fails to load-requirements

helm reset --force would clean a failed tiller deployment

- [ ] Fixes https://github.com/kubernetes/helm/issues/2441

ref(docs): remove unnecessary docs and clean up doc generator

ref(tiller): refactor tests into logical files

TestInstallRelease_WithChartAndDependencyNotes  -> tiller/release_install_test.go
TestInstallRelease_WrongTillerVersion -> tiller/release_install_test.go
TestInstallRelease_WithNotesRendered -> tiller/release_install_test.go
TestInstallRelease_TillerVersion -> tiller/release_install_test.go
TestInstallRelease_FailedHooks -> tiller/release_install_test.go
TestInstallRelease_ReuseName -> tiller/release_install_test.go
TestInstallRelease_WithNotes -> tiller/release_install_test.go
TestInstallRelease_NoHooks -> tiller/release_install_test.go
TestInstallRelease_DryRun -> tiller/release_install_test.go
TestInstallRelease -> tiller/release_install_test.go

ref(tiller): refactor tests into logical files

TestListReleasesByStatus -> tiller/release_list_test.go
TestListReleasesFilter -> tiller/release_list_test.go
TestListReleasesSort -> tiller/release_list_test.go
TestListReleases -> tiller/release_list_test.go
TestUpdateRelease_ResetReuseValues -> tiller/release_update_test.go
TestUpdateRelease_ResetValues -> tiller/release_update_test.go
TestUpdateRelease_ReuseValues -> tiller/release_update_test.go
TestUpdateReleaseNoChanges -> tiller/release_update_test.go
TestUpdateReleaseFailure -> tiller/release_update_test.go
TestUpdateReleaseNoHooks -> tiller/release_update_test.go
TestUpdateRelease -> tiller/release_update_test.go
TestRollbackReleaesFailure -> tiller/release_rollback_test.go

ref(tiller): refactor tests in logical files

Fixes https://github.com/kubernetes/helm/issues/2383

Sample `requirements.yaml` I used for test purpose was for wordpress chart

```dependencies:
- name: mariadb
  version: 0.5.10
  repository: https://kubernetes-charts.storage.googleapis.com/
  alias:
  - db1
  - db2
  - db3
```

TestRunReleaseTest -> tiller/release_testing_test.go
TestGetReleaseContent -> tiller/release_content_test.go
TestGetReleaseStatusDeleted -> tiller/release_status_test.go
TestGetReleaseStatus -> tiller/release_status_test.go
TestRollbackReleaseFailure -> tiller/release_rollback_test.go
TestRollbackReleaseNoHooks -> tiller/release_rollback_test.go
TestRollbackRelease -> tiller/release_rollback_test.go
TestUninstallReleaseWithKeepPolicy -> tiller/release_uninstall_test.go
TestUninstallPurgeDeleteRelease -> tiller/release_uninstall_test.go
TestUninstallReleaseNoHooks -> tiller/release_uninstall_test.go
TestUninstallPurgeRelease -> tiller/release_uninstall_test.go
TestUninstallRelease -> tiller/release_uninstall_test.go

Fixes https://github.com/kubernetes/helm/issues/2480

ref(tiller): refactor tiller APIs into logical files

*ReleaseServer.InstallRelease -> tiller/release_install.go
*ReleaseServer.UpdateRelease -> tiller/release_update.go

ref(tiller): refactor tiller APIs into logical files

*ReleaseServer.UninstallRelease -> tiller/release_uninstall.go
*ReleaseServer.ListReleases -> tiller/release_list.go

ref(tiller): refactor tiller APIs into logical files

*ReleaseServer.RollbackRelease -> tiller/release_rollback.go

ref(tiller): refactor tiller APIs into logical files

*ReleaseServer.GetReleaseContent -> tiller/release_content.go
*ReleaseServer.GetReleaseStatus -> tiller/release_status.go

ref(tiller): refactor release_server.go APIs into logical files.

*ReleaseServer.RunReleaseTest -> tiller/release_testing.go
*ReleaseServer.GetVersion     -> tiller/release_version.go

If git has autosetuprebase enabled pulling will fail without a
descriptive error message.

Adds a generic logging interface to importable packages.

fix(helm): fix itermittent release testing failures