PluginManager: documentation fixes.
Removed annoying Doxygen workaround for #undef.
Utility: move out the return value.

Saves unnecessary copy.
Utility: added String::uppercase() utility.

YAGNI principle to the extreme.
Utility: simple command-line argument parser.
Utility: added non-const overloads for Arguments::parse().

Sadly conversion from char** to const char** isn't implicit.
Utility: using Arguments parser in corrade-rc.

Now it looks nice.
PluginManager: simplified testing for plugin load success.

Now having LoadState::Static as subset of LoadState::Loaded and removed
artificial limitation for newlib-based targets where only
LoadState::Static was present. You can now do this:

    if(manager.load("...") & LoadState::Loaded)

Instead of this (AARGH MY SANITY):

    #ifndef CORRADE_TARGET_NACL_NEWLIB
    if(manager.load("...") & (LoadState::Loaded|LoadState::Static))
    #else
    if(manager.load("...") & LoadState::Static)
    #endif
Utility: fixed Arguments documentation.
Merge branch 'master' into compatibility
GCC 4.5 compatibility: no range-based for.
GCC 4.5 compatibility: no std::extent::operator() here.
GCC 4.4 compatibility: no raw string literals.