Cleaned up test script and directory naming

- Removed old tests and test scripts
- Reorganize the block devices to live under one directory
- Plugged new test framework into Makefile

renamed:
- scripts/test_.py -> scripts/test.py
- tests_ -> tests
- {file,ram,test}bd/* -> bd/*

It took a surprising amount of effort to make the Makefile behave since
it turns out the "test_%" rule could override "tests/test_%.toml.test"
which is generated as part of test.py.

tests/test_format.toml

@@ -0,0 +1,103 @@
+[[case]] # simple formatting test
+code = '''
+    lfs_format(&lfs, &cfg) => 0;
+'''
+
+[[case]] # mount/unmount
+code = '''
+    lfs_format(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_unmount(&lfs) => 0;
+'''
+
+[[case]] # reentrant format
+reentrant = true
+code = '''
+    err = lfs_mount(&lfs, &cfg);
+    if (err) {
+        lfs_format(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, &cfg) => 0;
+    }
+    lfs_unmount(&lfs) => 0;
+'''
+
+[[case]] # invalid mount
+code = '''
+    lfs_mount(&lfs, &cfg) => LFS_ERR_CORRUPT;
+'''
+
+[[case]] # expanding superblock
+define.BLOCK_CYCLES = [32, 33, 1]
+define.N = [10, 100, 1000]
+code = '''
+    lfs_format(&lfs, &cfg) => 0;
+    lfs_mount(&lfs, &cfg) => 0;
+    for (int i = 0; i < N; i++) {
+        lfs_mkdir(&lfs, "dummy") => 0;
+        lfs_stat(&lfs, "dummy", &info) => 0;
+        assert(strcmp(info.name, "dummy") == 0);
+        lfs_remove(&lfs, "dummy") => 0;
+    }
+    lfs_unmount(&lfs) => 0;
+
+    // one last check after power-cycle
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_mkdir(&lfs, "dummy") => 0;
+    lfs_stat(&lfs, "dummy", &info) => 0;
+    assert(strcmp(info.name, "dummy") == 0);
+    lfs_unmount(&lfs) => 0;
+'''
+
+[[case]] # expanding superblock with power cycle
+define.BLOCK_CYCLES = [32, 33, 1]
+define.N = [10, 100, 1000]
+code = '''
+    lfs_format(&lfs, &cfg) => 0;
+    for (int i = 0; i < N; i++) {
+        lfs_mount(&lfs, &cfg) => 0;
+        // remove lingering dummy?
+        err = lfs_remove(&lfs, "dummy");
+        assert(err == 0 || (err == LFS_ERR_NOENT && i == 0));
+        
+        lfs_mkdir(&lfs, "dummy") => 0;
+        lfs_stat(&lfs, "dummy", &info) => 0;
+        assert(strcmp(info.name, "dummy") == 0);
+        lfs_unmount(&lfs) => 0;
+    }
+
+    // one last check after power-cycle
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_stat(&lfs, "dummy", &info) => 0;
+    assert(strcmp(info.name, "dummy") == 0);
+    lfs_unmount(&lfs) => 0;
+'''
+
+[[case]] # reentrant expanding superblock
+define.BLOCK_CYCLES = [2, 1]
+define.N = 24
+reentrant = true
+code = '''
+    err = lfs_mount(&lfs, &cfg);
+    if (err) {
+        lfs_format(&lfs, &cfg) => 0;
+        lfs_mount(&lfs, &cfg) => 0;
+    }
+
+    for (int i = 0; i < N; i++) {
+        // remove lingering dummy?
+        err = lfs_remove(&lfs, "dummy");
+        assert(err == 0 || (err == LFS_ERR_NOENT && i == 0));
+        
+        lfs_mkdir(&lfs, "dummy") => 0;
+        lfs_stat(&lfs, "dummy", &info) => 0;
+        assert(strcmp(info.name, "dummy") == 0);
+    }
+
+    lfs_unmount(&lfs) => 0;
+
+    // one last check after power-cycle
+    lfs_mount(&lfs, &cfg) => 0;
+    lfs_stat(&lfs, "dummy", &info) => 0;
+    assert(strcmp(info.name, "dummy") == 0);
+    lfs_unmount(&lfs) => 0;
+'''