Overhaul the directory structure

In order to match the directory structure of traditional projects,
rename the top-level lib/ directory to src/libcamera/. Other libraries
developed as part of the project will later find a home in src/.

Split the libcamera header files in three categories: public headers
describing the public API in include/libcamera/, internal headers
describing the internal API in src/libcamera/include/, and private
headers local to one or a small number of compilation units along the
corresponding .cpp files. As no internal header exists yet the
src/libcamera/include/ directory is created empty as the build system
would fail otherwise.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/libcamera/main.cpp

@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2018, Google Inc.
+ *
+ * main.cpp - libcamera main class
+ */
+
+#include <iostream>
+#include <libcamera/libcamera.h>
+
+using std::cout;
+using std::endl;
+
+void libcamera::init_lib(void)
+{
+	cout << "Lib Camera Init" << endl;
+}

src/libcamera/meson.build

@@ -0,0 +1,11 @@
+sources = ['main.cpp']
+
+includes = [
+    libcamera_includes,
+    include_directories('include'),
+]
+
+libcamera = shared_library('camera',
+                           sources,
+                           install : true,
+                           include_directories : includes)

src/meson.build

@@ -0,0 +1 @@
+subdir('libcamera')