Improve oh-my-bash functionality

* Implement aliases, completion in oh-my-bash
 * Added default themes from Bash-it
 * Fixed few issues

themes/mbriggs/mbriggs.theme.sh

@@ -0,0 +1,34 @@
+# ------------------------------------------------------------------#
+#          FILE: mbriggs.zsh-theme                                  #
+#            BY: Matt Briggs (matt@mattbriggs.net)                  #
+#      BASED ON: smt by Stephen Tudor (stephen@tudorstudio.com)     #
+# ------------------------------------------------------------------#
+
+SCM_THEME_PROMPT_DIRTY="${red}⚡${reset_color}"
+SCM_THEME_PROMPT_AHEAD="${red}!${reset_color}"
+SCM_THEME_PROMPT_CLEAN="${green}✓${reset_color}"
+SCM_THEME_PROMPT_PREFIX=" "
+SCM_THEME_PROMPT_SUFFIX=""
+GIT_SHA_PREFIX=" ${yellow}"
+GIT_SHA_SUFFIX="${reset_color}"
+
+function git_short_sha() {
+  SHA=$(git rev-parse --short HEAD 2> /dev/null) && echo "$GIT_SHA_PREFIX$SHA$GIT_SHA_SUFFIX"
+}
+
+function prompt() {
+    local return_status=""
+    local ruby="${red}$(ruby_version_prompt)${reset_color}"
+    local user_host="${green}\h${reset_color}"
+    local current_path="\w"
+    local n_commands="\!"
+    local git_branch="$(git_short_sha)$(scm_prompt_info)"
+    local prompt_symbol='λ'
+    local open='('
+    local close=')'
+    local prompt_char=' \$ '
+
+    PS1="\n${n_commands} ${user_host} ${prompt_symbol} ${ruby} ${open}${current_path}${git_branch}${close}${return_status}\n${prompt_char}"
+}
+
+safe_append_prompt_command prompt