FindThreads: replace MATCHES with STREQUAL
FindThreads: avoid useless checks if a thread library is already found
FindThreads: simplify checking for SunOS
cmLocalUnixMakefileGenerator3: Re-organize ConvertToQuotedOutputPath

Use one code path whether the components list is empty or not.
Fix indentation accordingly.
Makefile: Generate single-quoted linker lines for Watcom on Windows

Drop the CMAKE_NO_QUOTED_OBJECTS internal variable from the Makefile
generators.  The underlying problem is with the Watcom linker, not with
WMake.  The Watcom linker wants object files to be single-quoted since
it does its own parsing of the Windows process command-line string.  Add
<LINK-RULE>_USE_SINGLE_QUOTE platform information variables to tell the
generators to use single quotes for object files on link lines.
Merge topic 'threads-cleanup' into next

693f8bf3 FindThreads: simplify checking for SunOS
858ce31f FindThreads: avoid useless checks if a thread library is already found
fdf7bd27 FindThreads: replace MATCHES with STREQUAL
Merge topic 'link-line-quoting' into next

f4796b40 Makefile: Generate single-quoted linker lines for Watcom on Windows
e348fa57 cmLocalUnixMakefileGenerator3: Re-organize ConvertToQuotedOutputPath