Introduce new glibc-doc.noarch subpackage (#1346925)
    
    The info pages of The GNU C Library Reference Manual included in the
    devel subpackage, were (slightly) increasing the installed size of
    systems that required the devel object files but not the manual.
    
    In addition to this, a number of unnecessary files (READMEs, NEWS,
    INSTALL, and an example gai.conf) were included in either the main
    package or the common subpackage.
    
    This commit introduces a new glibc-doc.noarch subpackage and moves the
    info pages from the devel subpackage and the debugger interface
    documentation from the main package into glibc-doc.  It also removes all
    the unnecessary documentation-like files mentioned above.