Fix potential HLS leakage in mythtranscode, found by Coverity

Fixes 'Resource Leak' Coverity IDs 1025906, 1025907, and 1025908 along
with a few other potential resource leaks of similar nature regarding
HLS and the AVFormatWriters it uses in transcode.cpp.
Fix cut-and-paste error in test_audioconvert's .gitignore
Check the return value of rename in httplivestream.cpp

Static analysis (coverity) detected un unchecked return
value from rename.  Add in the check, and log the error
in the (unlikely) event the rename fails.

Fixes coverity 746746
Fixes #11590.

Signed-off-by: Chris Pinkham <cpinkham@mythtv.org>
Fixes for several mythtranscode Coverity IDs

- Initialize m_last_audiotime in AudioReencodeBuffer ctor. ID 746889.
- Initialize totalFrames in Cutter ctor. ID 1025912.
- Check return value of preview image rename() call in main.cpp.  ID 746754.
- Execution can not reach "NULL" in mpeg2fix.cpp. ID 746800.
Several mythfrontend Coverity fixes

"Uninitialized pointer field" issues:
- m_hd in AudioTest. ID 746876.
- m_MPCM in AudioAdvancedSettings. ID 700946.  (unused variable removed)
- m_progressDialog in VideoSetupWizard. ID 746882.
- m_preview in ThemeChooser. ID 746883.
AudioReencodeBuffer: Remove m_bits which isn't used anywhere

Refs Coverity ID 746889
AudioTest: also initialise m_button missed in 54328bd25

There's a code path in the ctor where m_button could be left uninitialised and
that upsets Coverity. Refs ID 746876.
AudioAdvancedSettings: also remove m_triggerMPCM missed in 54328bd25

Refs Coverity ID 700946.
DTC::BlurayInfo: fix some uninitialised variables in the ctors

Fixes Coverity IDs 700892 and 700893.
ChannelInfoList: fix coverity ID 700894 Uninitialized scalar field

In DTC::?ChannelInfoList::ChannelInfoList(): A scalar field is not
initialized by the constructor.
RecRuleList: fix coverity ID 700895 Uninitialized scalar field

In DTC::RecRuleList::RecRuleList(): Several scalar fields are not initialized
by the constructor.
ViewScheduled: fix coverity ID 746886 Uninitialized pointer field

In ViewScheduled::ViewScheduled(): Several fields are not initialized in the
constructor.
CustomPriority: fix coverity ID 746878 Uninitialized pointer field

In CustomPriority::CustomPriority(): Several fields are not initialized
in the constructor.
CustomEdit: fix coverity ID 746877 Uninitialized pointer field

In CustomEdit::CustomEdit(): Several pointer fields are not initialized
in the constructor.
GuideGrid: fix coverity ID 1023903 Uninitialized pointer field

In GuideGrid::GuideGrid(): Several fields are not initialized in the
constructor.
LCDServer: fix coverity ID 746888 Uninitialized pointer field

In LCDServer::LCDServer(): There is a code path where m_lastSocket is not
initialized in the constructor.
LCDProcClient: fix coverity ID 746887 Uninitialized scalar field

In LCDProcClient::LCDProcClient(): Several fields are not initialized by the
constructor.
Merge remote-tracking branch 'upstream/master'