Specify runtime parameters in TOML format config file

In addition to specifying parameters in the command line and environment variables, you can now omit all parameters and provide a config file.

Example:

./documize myconfig.conf

Note: there is no switch setting, just provide the filename as an argument.

Fixes #243

vendor/github.com/BurntSushi/toml/Makefile

@@ -0,0 +1,19 @@
+install:
+	go install ./...
+
+test: install
+	go test -v
+	toml-test toml-test-decoder
+	toml-test -encoder toml-test-encoder
+
+fmt:
+	gofmt -w *.go */*.go
+	colcheck *.go */*.go
+
+tags:
+	find ./ -name '*.go' -print0 | xargs -0 gotags > TAGS
+
+push:
+	git push origin master
+	git push github master
+