Added two new sorting functions and a way to increase/decrease priorities easily

See README for more details:

<leader>s@ - sort by @contexts
<leader>s+ - sort by +projects
<leader>j  - decrease priority
<leader>k  - increase priority

README.markdown

@@ -10,6 +10,14 @@ mappings, to help with edition of these files:
 
 `<leader>-s` : Sort the file
 
+`<leader>-s+` : Sort the file on +Projects
+
+`<leader>-s@` : Sort the file on @Contexts
+
+`<leader>-j` : Lower the priority (cursor must by on priority)
+
+`<leader>-k` : Increase the priority (cursor must by on priority)
+
 `<leader>-d` : Insert the current date
 
 `date<tab>`  : (Insert mode) Insert the current date

ftplugin/todo.vim

@@ -45,6 +45,47 @@ if !hasmapto("<leader>s",'n')
 if !hasmapto("<leader>s",'n')
     nnoremap <script> <silent> <buffer> <leader>s :sort<CR>
 endif
+
+if !hasmapto("<leader>s@",'n')
+    nnoremap <script> <silent> <buffer> <leader>s@ :sort /.\{-}\ze@/ <CR>
+endif
+
+if !hasmapto("<leader>s+",'n')
+    nnoremap <script> <silent> <buffer> <leader>s+ :sort /.\{-}\ze+/ <CR>
+endif
+
+" Increment and Decrement The Priority
+:set nf=octal,hex,alpha
+
+function! TodoTxtPrioritizeIncrease()
+    "normal! 0f)h<C-a>
+    normal! 0f)h

+endfunction
+
+function! TodoTxtPrioritizeDecrease()
+    "normal! 0f)h<C-a>
+    normal! 0f)h
+endfunction
+
+if !hasmapto("<leader>j",'n')
+    "nnoremap <script> <silent> <buffer> <leader>j 0f)h<C-a>
+    nnoremap <script> <silent> <buffer> <leader>j :call TodoTxtPrioritizeIncrease()<CR>
+endif
+
+if !hasmapto("<leader>j",'v')
+    "vnoremap <script> <silent> <buffer> <leader>j 0f)h<C-a>
+    vnoremap <script> <silent> <buffer> <leader>j :call TodoTxtPrioritizeIncrease()<CR>
+endif
+
+if !hasmapto("<leader>k",'n')
+    "nnoremap <script> <silent> <buffer> <leader>k 0f)h<C-x>
+    nnoremap <script> <silent> <buffer> <leader>k :call TodoTxtPrioritizeDecrease()<CR>
+endif
+
+if !hasmapto("<leader>k",'v')
+    "vnoremap <script> <silent> <buffer> <leader>k 0f)h<C-x>
+    vnoremap <script> <silent> <buffer> <leader>k :call TodoTxtPrioritizeDecrease()<CR>
+endif
 
 " Insert date {{{2
 if !hasmapto("date<Tab>",'i')