Move the replicant dragger hand to lower-right corner of NoteWindow

[emily0618]

• Change NoteWindow to B_TITLED_WINDOW to make room for the dragger
• Make the scroll view fill the gap left by the moved dragger
• Resize NoteWindow to the correct height after opening a file
• Set fNoteText to the target of scrollview after opening a file
• Change background color of NoteText view instead of NoteView
• Set background color of NoteView and the dragger to the default
• Move the dragger to the lower-right corner of the window

Fixes #39. May also fix #36.

[emily0618]

Will update the screenshot in README.md after this pull request is approved or merged.

[emily0618]

Went ahead and updated the screenshot.

[owenca]

Nice! BTW @R4H33M already created PR #49 for the crash.