Add initial column implementation for psq

Author: keeperofdakeys

src/psq/columns.rs

@@ -0,0 +1,11 @@
+// FIXME: This may be better in procps
+enum PidColumns {
+    // Columns go here
+}
+
+// Implement FromStr to allow parsing a list of columns specified by a user
+// impl FromStr for PidColumns {
+
+
+// Implement ToStr to get a list of columns specified by a user
+// impl ToStr for PidColumns {

src/psq/main.rs

@@ -12,6 +12,8 @@ use procrs::pid::*;
 use procrs::TaskId;
 use argparse::{ArgumentParser, StoreTrue, Store};
 
+mod columns;
+
 fn main() {
     let opts = parse_args();
     let (query, long, perf, verbose, tree, threads) =