Added usermode unmounter and mounts parser

+ Added a mounts parser implementation using mntent API.
+ Added logging functions.
+ Added usermode unmounter which calls unshare pre app-specialization.
* Updated module.prop.

module/jni/mount_parser.cpp

@@ -0,0 +1,83 @@
+#include <string>
+#include <sstream>
+#include <vector>
+#include <unordered_map>
+
+#include <mntent.h>
+
+#include "mount_parser.hpp"
+#include "logging.hpp"
+
+mount_entry_t::mount_entry_t(::mntent *entry)
+    : fsname(entry->mnt_fsname), dir(entry->mnt_dir), type(entry->mnt_type), freq(entry->mnt_freq), passno(entry->mnt_passno)
+{
+    parseMountOptions(entry->mnt_opts);
+}
+
+const std::string &mount_entry_t::getFsName() const
+{
+    return fsname;
+}
+
+const std::string &mount_entry_t::getMountPoint() const
+{
+    return dir;
+}
+
+const std::string &mount_entry_t::getType() const
+{
+    return type;
+}
+
+const std::unordered_map<std::string, std::string> &mount_entry_t::getOptions() const
+{
+    return opts_map;
+}
+
+int mount_entry_t::getDumpFrequency() const
+{
+    return freq;
+}
+
+int mount_entry_t::getPassNumber() const
+{
+    return passno;
+}
+
+void mount_entry_t::parseMountOptions(const std::string &input)
+{
+    std::istringstream iss(input);
+    std::string token;
+    while (std::getline(iss, token, ','))
+    {
+        std::istringstream tokenStream(token);
+        std::string key, value;
+
+        if (std::getline(tokenStream, key, '='))
+        {
+            std::getline(tokenStream, value); // Put what's left in the stream to value, could be empty
+            opts_map[key] = value;
+        }
+    }
+}
+
+std::vector<mount_entry_t> parseMountsFromPath(const char *path)
+{
+    std::vector<mount_entry_t> result;
+
+    FILE *file = setmntent(path, "r");
+    if (file == NULL)
+    {
+        LOGE("setmntent(\"%s\", \"r\") returned NULL: %d (%s)", path, errno, strerror(errno));
+        return result;
+    }
+
+    struct mntent *entry;
+    while ((entry = getmntent(file)) != NULL)
+    {
+        result.emplace_back(mount_entry_t(entry));
+    }
+
+    endmntent(file);
+    return result;
+}