Improve completion text search and ordering

This is an attempt to improve the quality of completion results.

- Change text query from `title:~term` to `core:~term` to search both
  titles and bodies.
- Order results first by rank and then by primary result field.

Author: jparise

autoload/phabricator.vim

@@ -61,7 +61,7 @@ function! s:api_root() abort
   return api_root
 endfunction
 
-function! s:request(method, order, query) abort
+function! s:request(method, params) abort
   if !executable('curl')
     call s:throw('cURL is required')
   endif
@@ -80,10 +80,9 @@ function! s:request(method, order, query) abort
   call extend(args, ['-A', 'vim-phabricator'])
   call extend(args, ['-d', 'api.token=' . token])
   call extend(args, ['-d', 'queryKey=active'])
-  call extend(args, ['-d', 'order[0]=' . a:order])
-  if !empty(a:query)
-    call extend(args, ['-d', 'constraints[query]=title%3A~' . a:query])
-  endif
+  for [key, value] in items(a:params)
+    call extend(args, ['-d', key . '=' . value])
+  endfor
   call add(args, s:api_root() . a:method)
 
   let data = system('curl ' . join(args))
@@ -100,13 +99,19 @@ function! s:request(method, order, query) abort
 endfunction
 
 function! phabricator#query_projects(query) abort
-  let items = s:request('project.search', 'name', a:query)
-  return filter(items, 'v:val.slug =~# "^' . a:query . '"')
+  return s:request('project.search', {
+        \ 'order[0]': 'rank',
+        \ 'order[1]': 'name',
+        \ 'constraints[query]': 'core%3A~' . a:query,
+        \ })
 endfunction
 
 function! phabricator#query_users(query) abort
-  let items = s:request('user.search', 'username', a:query)
-  return filter(items, 'v:val.username =~# "^' . a:query . '"')
+  return s:request('user.search', {
+        \ 'order[0]': 'rank',
+        \ 'order[1]': 'username',
+        \ 'constraints[query]': 'core%3A~' . a:query,
+        \ })
 endfunction
 
 function! phabricator#complete(findstart, base) abort