#12 Fix hardware bugs

[bjohan]

Fix bugs that are present in the V2 hardware.

• Pull up on reset, not pull down DOH
• Add DC level resistors and DC blocking capacitor to AF_IN
• Add DC block on MOD_OUT

[bjohan]

• Description has changed:

Diff:

--- old
+++ new
@@ -2,3 +2,4 @@

 * Pull up on reset, not pull down *DOH*
 * Add DC level resistors and DC blocking capacitor to AF_IN
+* Add DC block on MOD_OUT