Windows installer: release 4.5

[dinkypumpkin]

NOTE:  If you have a working Windows get_iplayer installation, you do 
*not* need to upgrade.  This is a bug fix release aimed at new installs. 
  However, if you do want to upgrade components for some reason, 
download this new installer release and use it in preference to any old 
version you may already have.  See below.

This release fixes a bug that prevents updated installer configurations 
from propagating to fresh installs.  This was at least one of the causes 
behind recent reports of new users needing to run the installer multiple 
times to get updates to LAME, etc.  One of the main reasons for 
rewriting the installer was to create a mechanism for configuration 
updates.  Since that mechanism was partially broken - and working on the 
premise that first impressions count - I decided to go ahead and push a 
new release.

The new release is in the usual place:

http://www.infradead.org/get_iplayer_win/get_iplayer_setup_latest.exe

Along with this release, the installer configuration has been changed as 
follows:

LAME: Reverted to version 3.98.4. Version 3.99 builds are too volatile. 
  There have been 4 builds in 2 weeks, breaking the installer each time. 
  When 3.99 first appeared, I didn't notice that the old 3.98.4 build 
had actually been renamed rather than removed, so I've reverted to that 
build.  Whether or not you upgraded to 3.99, there is *no* reason to 
change your current installation.  As was discussed in an earlier 
thread, LAME is an unused vestigial appendage of get_iplayer and is 
likely to be removed from future releases.

RTMPDump: Updated to 2.4-git-6230845, the latest Windows build available 
from the RTMPDump site.  Again, there is *no* reason that I'm aware of 
for current users to upgrade, but since I was pushing a new installer 
release I took the opportunity to incorporate this newer build.  If 
nothing else, it will save a bit of time for folks like those who have 
been needlessly installing it themselves.