Fix interaction with idris client

The Vim integration was actually vulnerable to
shell injection attacks. This did not yet become
obvious because variables with quotes did not get
sent to the client properly. By fixing this the
attack became possible. I'm using shellescape to
tackle this issue.

after/ftplugin/idris.vim

@@ -0,0 +1,3 @@
+setlocal comments=s1fl:{-,mb:-,ex:-},:--
+setlocal formatoptions-=cro formatoptions+=j
+setlocal iskeyword+='

ftplugin/idris.vim

@@ -70,7 +70,7 @@ endfunction
 
 function! IdrisReload(q)
   w
-  let file = expand("%:p")
+  let file = shellescape(expand("%:p"))
   let tc = system("idris --client ':l " . file . "'")
   if (! (tc is ""))
     call IWrite(tc)
@@ -85,7 +85,7 @@ endfunction
 
 function! IdrisReloadToLine(cline)
   w
-  let file = expand("%:p")
+  let file = shellescape(expand("%:p"))
   let tc = system("idris --client ':lto " . a:cline . " " . file . "'")
   if (! (tc is ""))
     call IWrite(tc)
@@ -95,7 +95,7 @@ endfunction
 
 function! IdrisShowType()
   w
-  let word = expand("<cword>")
+  let word = shellescape(expand("<cword>"))
   let cline = line(".")
   let tc = IdrisReloadToLine(cline)
   if (! (tc is ""))
@@ -109,7 +109,7 @@ endfunction
 
 function! IdrisShowDoc()
   w
-  let word = expand("<cword>")
+  let word = shellescape(expand("<cword>"))
   let ty = system("idris --client ':doc " . word . "'")
   call IWrite(ty)
 endfunction
@@ -118,7 +118,7 @@ function! IdrisProofSearch(hint)
   let view = winsaveview()
   w
   let cline = line(".")
-  let word = expand("<cword>")
+  let word = shellescape(expand("<cword>"))
   let tc = IdrisReload(1)
 
   if (a:hint==0)
@@ -143,7 +143,7 @@ function! IdrisMakeLemma()
   let view = winsaveview()
   w
   let cline = line(".")
-  let word = expand("<cword>")
+  let word = shellescape(expand("<cword>"))
   let tc = IdrisReload(1)
 
   if (tc is "")
@@ -163,7 +163,7 @@ function! IdrisRefine()
   let view = winsaveview()
   w
   let cline = line(".")
-  let word = expand("<cword>")
+  let word = shellescape(expand("<cword>"))
   let tc = IdrisReload(1)
 
   let name = input ("Name: ")
@@ -184,7 +184,7 @@ function! IdrisAddMissing()
   let view = winsaveview()
   w
   let cline = line(".")
-  let word = expand("<cword>")
+  let word = shellescape(expand("<cword>"))
   let tc = IdrisReload(1)
 
   if (tc is "")
@@ -203,7 +203,7 @@ function! IdrisCaseSplit()
   let view = winsaveview()
   w
   let cline = line(".")
-  let word = expand("<cword>")
+  let word = shellescape(expand("<cword>"))
   let tc = IdrisReloadToLine(cline)
 
   if (tc is "")
@@ -222,7 +222,7 @@ function! IdrisMakeWith()
   let view = winsaveview()
   w
   let cline = line(".")
-  let word = expand("<cword>")
+  let word = shellescape(expand("<cword>"))
   let tc = IdrisReload(1)
 
   if (tc is "")
@@ -242,7 +242,7 @@ function! IdrisAddClause(proof)
   let view = winsaveview()
   w
   let cline = line(".")
-  let word = expand("<cword>")
+  let word = shellescape(expand("<cword>"))
   let tc = IdrisReloadToLine(cline)
 
   if (tc is "")