Clean up text throughout project

- Remove trailing newlines from redis.conf
  - Fix comment misspelling
  - Clarifies zipEncodeLength usage and a C API mention (#1243, #1242)
  - Fix cluster typos (inspired by @papanikge #1507)
  - Fix rewite -> rewrite in a few places (inspired by #682)

Closes #1243, #1242, #1507

src/aof.c

@@ -73,7 +73,7 @@ void aofRewriteBufferReset(void) {
     listSetFreeMethod(server.aof_rewrite_buf_blocks,zfree);
 }
 
-/* Return the current size of the AOF rewite buffer. */
+/* Return the current size of the AOF rewrite buffer. */
 unsigned long aofRewriteBufferSize(void) {
     listNode *ln = listLast(server.aof_rewrite_buf_blocks);
     aofrwblock *block = ln ? ln->value : NULL;
@@ -202,7 +202,7 @@ int startAppendOnly(void) {
         redisLog(REDIS_WARNING,"Redis needs to enable the AOF but can't trigger a background AOF rewrite operation. Check the above logs for more info about the error.");
         return REDIS_ERR;
     }
-    /* We correctly switched on AOF, now wait for the rewite to be complete
+    /* We correctly switched on AOF, now wait for the rewrite to be complete
      * in order to append data on disk. */
     server.aof_state = REDIS_AOF_WAIT_REWRITE;
     return REDIS_OK;

src/sentinel.c

@@ -2106,7 +2106,7 @@ void sentinelPublishReplyCallback(redisAsyncContext *c, void *reply, void *privd
  * or sent directly to this sentinel via the (fake) PUBLISH command of Sentinel.
  *
  * If the master name specified in the message is not known, the message is
- * discareded. */
+ * discarded. */
 void sentinelProcessHelloMessage(char *hello, int hello_len) {
     /* Format is composed of 8 tokens:
      * 0=ip,1=port,2=runid,3=current_epoch,4=master_name,

src/util.c

@@ -385,7 +385,7 @@ int string2l(const char *s, size_t slen, long *lval) {
 }
 
 /* Convert a double to a string representation. Returns the number of bytes
- * required. The representation should always be parsable by stdtod(3). */
+ * required. The representation should always be parsable by strtod(3). */
 int d2string(char *buf, size_t len, double value) {
     if (isnan(value)) {
         len = snprintf(buf,len,"nan");

src/ziplist.c

@@ -183,7 +183,7 @@ static unsigned int zipIntSize(unsigned char encoding) {
     return 0;
 }
 
-/* Encode the length 'l' writing it in 'p'. If p is NULL it just returns
+/* Encode the length 'rawlen' writing it in 'p'. If p is NULL it just returns
  * the amount of bytes required to encode such a length. */
 static unsigned int zipEncodeLength(unsigned char *p, unsigned char encoding, unsigned int rawlen) {
     unsigned char len = 1, buf[5];