bunzip2/gunzip/uncompress/unlzma: merge into common code -

fix few corner cases, reduce size by 450 bytes. Update testsuite.

testsuite/bzcat.tests

@@ -0,0 +1,49 @@
+#!/bin/sh
+
+ext=bz2
+
+bb="busybox "
+
+unset LC_ALL
+unset LC_MESSAGES
+unset LANG
+unset LANGUAGE
+
+hello_gz() {
+    # Gzipped "HELLO\n"
+    #_________________________ vvv vvv vvv vvv - mtime
+    echo -ne "\x1f\x8b\x08\x00\x85\x1d\xef\x45\x02\x03\xf3\x70\xf5\xf1\xf1\xe7"
+    echo -ne "\x02\x00\x6e\xd7\xac\xfd\x06\x00\x00\x00"
+}
+
+hello_bz2() {
+    # Bzipped "HELLO\n"
+    echo -ne "\x42\x5a\x68\x39\x31\x41\x59\x26\x53\x59\x5b\xb8\xe8\xa3\x00\x00"
+    echo -ne "\x01\x44\x00\x00\x10\x02\x44\xa0\x00\x30\xcd\x00\xc3\x46\x29\x97"
+    echo -ne "\x17\x72\x45\x38\x50\x90\x5b\xb8\xe8\xa3"
+}
+
+prep() {
+    rm -f t*
+    hello_$ext >t1.$ext
+    hello_$ext >t2.$ext
+}
+
+check() {
+    eval $2 >t_actual 2>&1
+    if echo -ne "$expected" | cmp - t_actual; then
+	echo "$1: PASS"
+    else
+	echo "$1: FAIL"
+    fi
+}
+
+mkdir testdir 2>/dev/null
+(
+cd testdir || { echo "cannot cd testdir!"; exit 1; }
+
+expected="HELLO\nok\n"
+prep; check "bzcat: dont delete src" "${bb}bzcat t2.bz2; test -f t2.bz2 && echo ok"
+
+)
+rm -rf testdir