Remove unused variables

This fixes warnings with clang and gcc.
Add casts to avoid warnings about comparison between signed and unsigned

This fixes warnings with gcc.
Change integer literals to unsigned to avoid warnings about comparison between signed and unsigned

This fixes warnings in gcc.
Check the return value of fread

This silences warnings on linux/gcc.
Add a cast when converting from double to float

This fixes warnings with MSVC.
Merge pull request #1508 from mstorsjo/remove-unused-variables

Remove unused variables
Merge pull request #1509 from mstorsjo/fix-warnings-cast

Add casts to avoid warnings about comparison between signed and unsigned
Merge pull request #1510 from mstorsjo/unsigned-int-literals

Change integer literals to unsigned to avoid warnings about comparison between signed and unsigned
Merge pull request #1511 from mstorsjo/check-fread-return-value

Check the return value of fread
Merge pull request #1512 from mstorsjo/add-float-cast

Add a cast when converting from double to float
Merge pull request #1507 from ruil2/init

  remove repeat initialization
Remove a duplicated field in SWelsSvcCodingParam

The same field already exists in SEncParamExt. When the
initialization was deduplicated in ac404ce, this lead to
reading the now uninitialized field in SWelsSvcCodingParam,
instead of the properly initialized one in the base class.
add some traces for bitstream output
Merge pull request #1516 from mstorsjo/remove-duplicated-field

Remove a duplicated field in SWelsSvcCodingParam
Merge pull request #1515 from ruil2/add_nal_trace

add some traces for bitstream output
update max payload setting for gmp wrapper