Improve Makefile & shell configs

* Add cross platform support in Makefile

 * Add host-specific configurations support.

_profile

@@ -8,6 +8,11 @@
 # for ssh logins, install and configure the libpam-umask package.
 #umask 022
 
+# Host-specific alias definitions
+if [ -f "${HOME}/.host.profile" ]; then
+    . "${HOME}/.host.profile"
+fi
+
 # When running bash
 if [ -n "${BASH_VERSION}" ]; then
     # include .bashrc if it exists
@@ -27,7 +32,7 @@ if [ -e "${HOME}/bin" ]; then
 fi
 
 # Add cargo
-if [ -e "${HOME}/.cargo/bin" ]; then
-    PATH="${HOME}/.cargo/bin:${PATH}"
+if [ -f "${HOME}/.cargo/env" ]; then
+    . "$HOME/.cargo/env"
 fi