Improve render exception error messages

When exceptions are encountered during layout rendering, the user
experience isn't very good - the exceptions are sent to the IDE log,
and the layout editor view adds the error message from the exception
(which can sometimes be something like just "2", which is the case for
an ArrayIndexOutOfBoundsException for example).

This changeset improves this a bit:

* First, when the error message is just an exception error message,
  it's prefixed by a message stating that an exception was raised
  during layout rendering.

* Second, the first exception encountered is now shown in the layout
  editor itself. Only the frames that are part of the android view
  hierarchy is shown; all the frames from layoutlib and on down into
  the IDE are omitted. Frames that are probably part of the user's
  code (meaning they're not in the android.* or java.* namespaces) are
  hyperlinkable.

* This also includes exceptions encountered during class
  initialization. In this case, the tip message that View#isInEditMode
  can be used to do conditional code is displayed in bold.

This changeset also fixes some bugs in the SourceRevealer such that it
can handle constructors, and such that it will use the line number to
pinpoint a line within a method (as long as the line number is in the
correct range).

Change-Id: I43b635eb24b8e0e64988958c56bdb7dbc1af7221