Unable to increase partition size with subsequent blocking partition

I can't make my main Macintosh HD partition bigger. It's limited by the partition in the middle, which seems to be frozen, I can't move it down to make space for my main partition. Also I can't seem to delete it. The format of disk0s4 is Mac OS Extended (Journaled).

Some background, I created a partition to experiment with bootcamp to use windows. Once done I deleted that new partition, it became a no-man's land that neither partition can claim.

As a seperate issue, boot camp assistant has been giving me this error:

Anyone has any ideas? Much appreciated!

The closest problem I've found is here, this is a FAT partition. Unable to increase Macintosh HD partition size with data in a subsequent partition

iPartition

For all my partitioning, I use and recommend iPartition. It will allow you to resize partitions without deleting any data. It will automatically move partitions if necessary to allow resizing into free space that is located after the partition.

iPartition’s ability to automatically rearrange your existing partitions when necessary, makes iPartition the easiest partitioning tool that you’ll ever use.

GParted

iPartition has a non-functional demo mode, which is quite misleading. If you don't want to pay the $50 for it, the GParted live CD/USB is a good Free alternative.

It can't resize HFS+ partitions according to Wikipedia but it can copy and move them, and then you should be able to resize using the built-in Disk Utility.