bashrc: Terminal.app improvements, aliases broken out

On the Mac terminal sessions don't seem to retain the same
environment as the one that parses their .bashrc files.  So, to
overcome that, all aliases and PATH/variable changes are done in
.profile (or files sourced by .profile).

There aren't any .profiles checked in yet, but stay tuned ;-)

.bashrc.mac

@@ -1,4 +1,14 @@
-alias ls='ls -G'
+#!/usr/bin/env bash
+
+# System-wide .bashrc file for interactive bash(1) shells.
+if [ -z "$PS1" ]; then
+   return
+fi
+
+# Make bash check its window size after a process completes
+shopt -s checkwinsize
+
+[ -r "/etc/bashrc_$TERM_PROGRAM" ] && . "/etc/bashrc_$TERM_PROGRAM"
 
 blsc() { alias ls='ls -G'; }
 unuu-me() { PATH="$(sed 's/\/opt\/local\/libexec\/uutils://' <<<$PATH)"; blsc; }