conf_get: Get config value from in-memory cache or from file...
In rappster/confx: Extended functionality for YAML-based config files

TODO-20191026-1: Write doc for conf_get()

conf_get(
  value = character(),
  from = "config.yml",
  dir_from = Sys.getenv("R_CONFIG_DIR", getwd()),
  config = Sys.getenv("R_CONFIG_ACTIVE", "default"),
  use_parent = TRUE,
  sep = "/",
  sep_opt_name = "_",
  resolve_references = TRUE,
  force_from_file = FALSE,
  leaf_as_list = FALSE,
  verbose = FALSE
)

`value`	[character]
`from`	[character]
`dir_from`	[character]
`config`	[character]
`use_parent`	[logical]
`sep`	[character]
`sep_opt_name`	[character]
`resolve_references`	[logical]
`force_from_file`	[logical]
`leaf_as_list`	[logical]
`verbose`	[logical]