Unit tests

Commands	Short Commands	Description	Example Usage
singlecompile	`sc`	Compile a single `.c` file to `.wasm` and `.cwasm`.	`./wasmtest.sh sc file.c`
singlerun	`sr`	Run a single previously compiled `.wasm`/`.cwasm`file.	`./wasmtest.sh sr file.c`
single	`s`	Compile and run a single `.c` file in sequence (first compile to WASM, then run).	`./wasmtest.sh s file.c`
allcompile	`ac`	Compile all `.c` test files in `$LIND_WASM_BASE/tests/unit-tests`.	`./wasmtest.sh ac`
allrun	`ar`	Run all compiled tests in `$LIND_WASM_BASE/tests/unit-tests`.	`./wasmtest.sh ar`
all	`a`	Compile and run all test files in `$LIND_WASM_BASE/tests/unit-tests`.	`./wasmtest.sh a`
filescompile, filecompile	`fc`	Compile test files listed in a user-provided text file (each line should contain one `.c` filename).	`./wasmtest.sh fc filelist.txt`
filesrun, filerun	`fr`	Run test files listed in a user-provided text file (assumes the `.wasm`/`.cwasm` files are already compiled).	`./wasmtest.sh fr filelist.txt`
files, file	`f`	Compile and run test files listed in a user-provided text file (each line should contain one `.c` filename).	`./wasmtest.sh f filelist.txt`
`--timeout=<seconds>` (optional)	(none)	Set a custom test timeout (in seconds). Default: 5 seconds.	`./wasmtest.sh single file.c --timeout=10`

LIND_WASM_BASE: Defaults to /home/lind/lind-wasm. You can override it:
```bash export LIND_WASM_BASE="/custom/path/to/lind-wasm"
<file>.c: A single test file to compile or run, found in $LIND_WASM_BASE/tests/unit-tests.
<filelist>: A text file containing one .c filename per line, found in $LIND_WASM_BASE/tests/unit-tests.