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

@@ -1,6 +1,8 @@
+#!/usr/bin/env bash
+
 command -v port >/dev/null &&
     command -v uname >/dev/null &&
-    [ $(uname) == 'Darwin' ] && . .bashrc.mac
+    [ $(uname) == 'Darwin' ] &&  . /opt/local/etc/bashrc.mac
 
 simplefind() { find . -iname '*'"$@"'*'; }
 simpleplay() {
@@ -8,8 +10,3 @@ simpleplay() {
     | xargs -0 mpv --no-audio-display \
   ;
 }
-
-# Python
-alias mk-venv='python -m venv .venv'
-alias do-venv='. .venv/bin/activate'
-alias rm-venv='rm -rf .venv'