This commit moves all of the libraries under a common directory called libs/. This most certainly break libcxx and uClibc++ for now.

Squashed commit of the following:

    libs/libxx:  Fix some confusing in naming.  If the directory is called libxx, then the library must be libxx.a (unless perhaps LIBCXX is selected).
    libs/:  Fix paths in moved library directories.
    libs:  Brute force move of libc, libnx, and libxx to libs.  Cannot yet build it in that configuration.

libs/libc/wqueue/Kconfig

@@ -0,0 +1,38 @@
+#
+# For a description of the syntax of this configuration file,
+# see the file kconfig-language.txt in the NuttX tools repository.
+#
+
+menu "User Work Queue Support"
+	depends on (BUILD_PROTECTED || BUILD_KERNEL) && !DISABLE_SIGNALS
+
+config LIB_USRWORK
+	bool "User mode worker thread"
+	default n
+	---help---
+		User space work queues can also be made available for deferred
+		processing in the NuttX kernel build.
+
+if LIB_USRWORK
+
+config LIB_USRWORKPRIORITY
+	int "User mode priority worker thread priority"
+	default 100
+	---help---
+		The execution priority of the user-mode priority worker thread.  Default: 100
+
+config LIB_USRWORKPERIOD
+	int "User mode worker thread period"
+	default 100000
+	---help---
+		How often the lower priority worker thread checks for work in units
+		of microseconds. Default: 100*1000 (100 MS).
+
+config LIB_USRWORKSTACKSIZE
+	int "User mode worker thread stack size"
+	default 2048
+	---help---
+		The stack size allocated for the lower priority worker thread.  Default: 2K.
+
+endif # LIB_USRWORK
+endmenu # User Work Queue Support