Add configuration for bash

- Add ~/.bashrc
  + Configure on how the `history` works
  + Enable nicer `cd` and globbing behavior
  + Enable tab completion, even for aliases
  + Add some more stuff from Debian's ~/.bashrc
- Add ~/.bash_logout clearing the screen
- Add stubs for ~/.bash_login and ~/.bash_profile
  that redirect to ~/.profile
- Add ~/.bash_completion
- Ensure ~/.local/state/bash/ exists

.profile

@@ -1,10 +1,18 @@
 #!/bin/sh
 
 # Main setup file executed for all kinds of shells
+#
+# For `bash`, if the following files exist,
+# they have precedence over this file:
+#  - ~/.bash_login
+#  - ~/.bash_profile
+#
+# So, we make both source this file,
+# and thus preserve the load order either way!
 
 
 # Prevent loading ~/.profile twice in `bash`
-export PROFILE_LOADED=1
+PROFILE_LOADED=1
 
 
 # Basic utilities
@@ -77,7 +85,3 @@ _prepend_to_path "$HOME/.local/bin"
 if [ -n "$BASH_VERSION" ] && [ -f "$HOME/.bashrc" ]; then
     . "$HOME/.bashrc"
 fi
-
-
-# Ensure ~/.profile is loaded each time `bash` starts
-unset PROFILE_LOADED