Enhance test system

- Tests are now named
- Testlogs are preserved between runs
- Tests can be run through Valgrind Memcheck tool

test/testdata/invalid-unicode

@@ -1,88 +1,89 @@
+==== lone-invalid-utf-8 ====
 <EFBFBD>
 ====
 -1
 unable to decode byte 0xe5 at position 0
-========
+==== invalid-utf-8-in-string ====
 ["<22> <-- invalid UTF-8"]
 ====
 -1
 unable to decode byte 0xe5 at position 2
-========
+==== invalid-utf-8-in-array ====
 [<5B>]
 ====
 -1
 unable to decode byte 0xe5 at position 1
-========
+==== invalid-utf-8-in-identifier ====
 [a<>]
 ====
 -1
 unable to decode byte 0xe5 at position 2
-========
+==== invalid-utf-8-in-escape ====
 ["\u<>"]
 ====
 -1
 unable to decode byte 0xe5 at position 4
-========
+==== invalid-utf-8-after-backslash ====
 ["\<5C>"]
 ====
 -1
 unable to decode byte 0xe5 at position 3
-========
+==== invalid-utf-8-in-int ====
 [0<>]
 ====
 -1
 unable to decode byte 0xe5 at position 2
-========
+==== invalid-utf-8-in-bigger-int ====
 [123<32>]
 ====
 -1
 unable to decode byte 0xe5 at position 4
-========
+==== invalid-utf-8-in-real-after-e ====
 [1e<31>]
 ====
 -1
 unable to decode byte 0xe5 at position 3
-========
+==== invalid-utf-8-in-exponent ====
 [1e1<65>]
 ====
 -1
 unable to decode byte 0xe5 at position 4
-========
+==== lone-utf-8-continuation-byte ====
 ["<22>"]
 ====
 -1
 unable to decode byte 0x81 at position 2
-========
+==== overlong-ascii-encoding ====
 ["<22>"]
 ====
 -1
 unable to decode byte 0xc1 at position 2
-========
+==== restricted-utf-8 ====
 ["<22>"]
 ====
 -1
 unable to decode byte 0xfd at position 2
-========
+==== not-in-unicode-range ====
 ["<22><><EFBFBD><EFBFBD>"]
 ====
 -1
 unable to decode byte 0xf4 at position 2
-========
+==== overlong-3-byte-encoding ====
 ["<22><><EFBFBD> <-- overlong encoding"]
 ====
 -1
 unable to decode byte 0xe0 at position 2
-========
+==== overlong-4-byte-encoding ====
 ["<22><><EFBFBD><EFBFBD> <-- overlong encoding"]
 ====
 -1
 unable to decode byte 0xf0 at position 2
-========
+==== truncated-utf-8 ====
 ["<22><> <-- truncated UTF-8"]
 ====
 -1
 unable to decode byte 0xe0 at position 2
-========
+==== encoded-surrogate-half ====
 ["<22><><EFBFBD> <-- encoded surrogate half"]
 ====
 -1