vcs: Restructure vcs module

Just like writing and qutebrowser modules, restructured the version
control software module to make more use of dotter's ability to
precisely link files. All contained programs have a top-level directory
and all the files that correspond to that specific software lie beneath
in the directory tree.

vcs/gitignore/config/zsh/completions/_gitignore

@@ -0,0 +1,15 @@
+#compdef _gitignore gitignore
+#
+# Requires gitignore script in path
+#
+# Enables completion for zsh of gitignore function.
+
+_gitignore_get_command_list() {
+  curl -sL https://www.gitignore.io/api/list | tr ',' '\n'
+}
+
+_gitignore() {
+  _arguments \
+    '1::flags:((-f\:"Save output to .gitignore file in current directory"))' \
+    ":listopts: _values -s, 'modules' $(_gitignore_get_command_list)"
+}

vcs/gitignore/local/bin/gitignore

@@ -0,0 +1,79 @@
+#!/usr/bin/env sh
+#
+# Adds call to gitignore.sh api to automatically
+# generate a .gitignore file with the individual arguments
+# passed in included as ignored packages.
+#
+# Pass in -f as first argument to save the file as .gitignore
+# in the current directory in addition to printing to stdout.
+# Will *overwrite* any previous .gitignore file that exists in
+# current directory.
+#
+# When called without arguments will load all possible arguments
+# as fzf searchable list if fzf is in path.
+#
+# Enables completion for zsh in git/.config/shell/zshrc.d/_gitignore_completions.zsh
+
+__get_items() {
+  if [ "$1" = "" ]; then
+    echo "gitignore definition generation needs at least one argument."
+    exit 1
+  fi
+  if [ "$savetofile" = "true" ]; then
+    __call_url "$@" >>.gitignore
+  else
+    __call_url "$@"
+  fi
+}
+
+__call_url() {
+  IFS=","
+  curl -L -s https://www.gitignore.io/api/"$*"
+}
+
+gitignore() {
+  if [ "$1" = "-h" ] || [ "$1" = "--help" ]; then
+    usage
+    exit 0
+  # just print to stdout or save locally?
+  elif [ "$1" = "-f" ] || [ "$1" = "--file" ]; then
+    savetofile=true
+    shift
+  fi
+
+  IFS=","
+  if [ "$#" -eq 0 ]; then
+    if type fzf >/dev/null 2>&1; then
+      for item in $(__get_items list); do
+        echo "$item"
+      done | fzf --multi --ansi | paste -s -d "," - |
+        { read -r result && __get_items "$result"; }
+    else
+      usage
+    fi
+  else
+    __get_items "$@"
+  fi
+}
+
+usage() {
+  printf "%s\n" \
+    "" \
+    " gitignore     Quickly generate a gitignore definition." \
+    "" \
+    " Usage: gitignore [-h] [vim] [linux] [javascript] [...]" \
+    "" \
+    " Arguments:" \
+    "" \
+    "     -h | --help       Print out this help." \
+    "" \
+    "     -f | --file       Append gitignore definition to .gitignore file" \
+    "                       instead of stdout." \
+    "" \
+    "     Arguments will be passed along to gitignore.io for parsing and " \
+    "     gitignore definition generation. By default only prints to stdout." \
+    "" \
+    ""
+}
+
+gitignore "$@"