Don't normalize line endings from Buffer.setText

BufferChangeOperation now takes an options hash that
can specify whether line endings should be normalized.

This option is set to false when Buffer.setText is called.
This replaces the previous assignment of lineEndings to []
with a more explicit mechanism.

src/app/buffer-change-operation.coffee

@@ -9,7 +9,8 @@ class BufferChangeOperation
   newRange: null
   newText: null
 
-  constructor: ({@buffer, @oldRange, @newText}) ->
+  constructor: ({@buffer, @oldRange, @newText, @options}) ->
+    @options ?= {}
 
   do: ->
     @oldText = @buffer.getTextInRange(@oldRange)
@@ -52,7 +53,9 @@ class BufferChangeOperation
 
     startRow = oldRange.start.row
     endRow = oldRange.end.row
-    if suggestedLineEnding = @buffer.suggestedLineEndingForRow(startRow)
+
+    normalizeLineEndings = @options.normalizeLineEndings ? true
+    if normalizeLineEndings and suggestedLineEnding = @buffer.suggestedLineEndingForRow(startRow)
       lineEndings[index] = suggestedLineEnding for index in [0..lastLineIndex]
     @buffer.lines[startRow..endRow] = lines
     @buffer.lineEndings[startRow..endRow] = lineEndings

src/app/buffer.coffee

@@ -109,8 +109,7 @@ class Buffer
     @cachedMemoryContents ?= @getTextInRange(@getRange())
 
   setText: (text) ->
-    @lineEndings = []
-    @change(@getRange(), text)
+    @change(@getRange(), text, normalizeLineEndings: false)
 
   getRange: ->
     new Range([0, 0], [@getLastRow(), @getLastLine().length])
@@ -206,9 +205,9 @@ class Buffer
   delete: (range) ->
     @change(range, '')
 
-  change: (oldRange, newText) ->
+  change: (oldRange, newText, options) ->
     oldRange = Range.fromObject(oldRange)
-    operation = new BufferChangeOperation({buffer: this, oldRange, newText})
+    operation = new BufferChangeOperation({buffer: this, oldRange, newText, options})
     range = @pushOperation(operation)
     range