Remove Thoreau and Emerson from poetry sources.

mainline.py

@@ -67,8 +67,6 @@ MESSAGE_DISPLAY_SECS = 30 # how long a message holds the screen
 POETRY_SOURCES = {
     "Whitman":    "https://www.gutenberg.org/cache/epub/1322/pg1322.txt",
     "Dickinson":  "https://www.gutenberg.org/cache/epub/12242/pg12242.txt",
-    "Thoreau":    "https://www.gutenberg.org/cache/epub/205/pg205.txt",
-    "Emerson":    "https://www.gutenberg.org/cache/epub/2944/pg2944.txt",
     "Whitman II": "https://www.gutenberg.org/cache/epub/8388/pg8388.txt",
     "Rilke":      "https://www.gutenberg.org/cache/epub/38594/pg38594.txt",
     "Pound":      "https://www.gutenberg.org/cache/epub/41162/pg41162.txt",