Merge branch 'refactor'

This merges the libmaple refactor work into master.  The contents of
libmaple proper (/libmaple/) are almost completely incompatible with
previous APIs in master.  See /docs/source/libmaple/overview.rst for
more information on the new design.

Wirish incompatibilities are limited to the HardwareTimer class;
however, there are several new deprecations, most likely to be removed
in 0.1.0.

1 files changed, 15 insertions, 4 deletions

diff --git a/docs/source/usart.rst b/docs/source/usart.rst
index 3beb3fc..9506cc8 100644
--- a/docs/source/usart.rst
+++ b/docs/source/usart.rst
@@ -4,23 +4,34 @@
  USART
 =======
 
-.. contents::
+.. contents:: Contents
    :local:
 
 Hardware/Circuit Design
 -----------------------
 
+.. FIXME [0.0.10] UART4 and UART5
+.. FIXME [0.1.0] Maple Native and Mini info and links
+
 The Maple has 3 separate USART devices. In the most simple use case,
 the RX and TX pins are used to send data at a predetermined baudrate
 with the line voltage level relative to ground.  Their usage is
 documented in the :ref:`Serial Ports <lang-serial>` language reference
-page.
+page.  Which pins correspond to the USART TX and RX pins are given on
+your board's silkscreen, and also in the board-specific USART pin maps
+available here:
+
+* :ref:`Maple <maple-usart-map>`
+* :ref:`Maple RET6 Edition <maple-ret6-usart-map>`
+
+If you use a particular serial port, you cannot also use its
+communication pins for other purposes at the same time.
 
 Compatible Devices and Specifications
 -------------------------------------
 
-We have successfully used the Maple USART ports with an FT232R-based
-USB-serial converter at up to 115200 baud; higher speeds should
+We have successfully used the USART ports with an FT232R-based
+USB-serial converter at up to 115200 baud.  Higher speeds should
 certainly be possible.
 
 Recommended Reading