Add support for dropwizard input format (#2846)

Godeps

README.md

docs/DATA_FORMATS_INPUT.md

internal/config/config.go

internal/templating/engine.go

internal/templating/matcher.go

internal/templating/node.go

internal/templating/template.go

plugins/parsers/dropwizard/parser.go

plugins/parsers/dropwizard/parser_test.go

plugins/parsers/graphite/parser.go

plugins/parsers/graphite/parser_test.go

plugins/parsers/registry.go