Description of problem:
When using pull command with projectType=raw, if the project contains any documents that have been uploaded as raw documents, but the document name does not include an extension matching the type, a 500 error (caused by NullPointerException) is returned by the server.


Version-Release number of selected component (if applicable):
Server version 2.0.3

How reproducible:
Always


Steps to Reproduce:
1. Use curl to upload a raw document under a name with no extension
     e.g. curl -F type=txt -F file= -F hash=`md5sum document.txt | awk '{print $1}'`   -F first=true -F last=true   -H "X-Auth-User:USERNAME" -H "X-Auth-Token:API_KEY"    "SERVER/rest/file/source/PROJECT_SLUG/VERSION_SLUG?docId=document

     Note: docId=document has no file extension

2. Download zanata.xml for the project-version and ensure project type is raw (e.g. <project-type>raw</project-type>
3. From the directory containing zanata.xml, run zanata pull command (e.g. mvn zanata:pull)
  
Actual results:
500 internal server error when the process reaches the document from step 1. Some documents that have a matching extension may be pulled successfully, depending on the order that the documents are pulled.

Expected results:
All documents pulled successfully, regardless of document name.

Additional info:
Caused by use of document name to look up a file format adapter. Should use document type from database.