Trim down mime type overrides that are old or now pushed upstream

Related #206

lib/linguist/mimes.yml

@@ -23,40 +23,16 @@
 # Any additions or modifications (even trivial) should have corresponding
 # test change in `test/test_mime.rb`.
 
-# TODO: Lookup actual types
-application/octet-stream @a,blend,gem,graffle,ipa,lib,mcz,nib,o,ogv,otf,pfx,pigx,plgx,psd,sib,spl,sqlite3,swc,ucode,xpi
-
 # Please keep this list alphabetized
 application/java-archive @ear,war
-application/netcdf :8bit
-application/ogg @ogg
-application/postscript :base64
-application/vnd.adobe.air-application-installer-package+zip @air
-application/vnd.mozilla.xul+xml :8bit
-application/vnd.oasis.opendocument.presentation @odp
-application/vnd.oasis.opendocument.spreadsheet @ods
-application/vnd.oasis.opendocument.text @odt
-application/vnd.openofficeorg.extension @oxt
-application/vnd.openxmlformats-officedocument.presentationml.presentation @pptx
+application/octet-stream @o
 application/x-chrome-extension @crx
-application/x-iwork-keynote-sffkey @key
-application/x-iwork-numbers-sffnumbers @numbers
-application/x-iwork-pages-sffpages @pages
-application/x-ms-xbap @xbap :8bit
-application/x-parrot-bytecode @pbc
-application/x-shockwave-flash @swf
-application/x-silverlight-app @xap
 application/x-supercollider @sc :8bit
-application/x-troff-ms :8bit
-application/x-wais-source :8bit
-application/xaml+xml @xaml :8bit
 application/xslt+xml @xslt :8bit
 image/x-icns @icns
 text/cache-manifest @manifest
 text/plain @cu,cxx
 text/x-logtalk @lgt
-text/x-nemerle @n
 text/x-nimrod @nim
 text/x-ocaml @ml,mli,mll,mly,sig,sml
-text/x-rust @rs,rc
 text/x-scheme @rkt,scm,sls,sps,ss