config: Add a function to read a config file (WIP)

A new function that will read a TOML config file. Doesn't currently
access the filesystem. This commit is mostly supporting code to allow
that to work.

* Add the 'toml' crate
* `parse_args()`: Take a mutable `Config` and return that config instead
  of creating a new one. The recipe will now be to read the config from
  a file first and then pass that config to this function to be updated.
* Modify `c_parse_args()` to take a `*Config` and mirror the new method
  signature of `parse_args()`

1 files changed, 1 insertions, 0 deletions

diff --git a/Cargo.toml b/Cargo.toml
index 45b5883..17a080b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,6 +15,7 @@ objc = "0.2.5"
 serde = "1.0.58"
 serde_derive = "1.0.58"
 stderrlog = "0.4.1"
+toml = "0.4.8"
 xdg = "2.1.0"
 
 [build-dependencies]