increase number of supported PWM channels from 4 to 6

Approved-by: Gregory Nutt

Merged in w8jcik/apps/w8jcik/the-config_netutils_httpd_path-constant--1488710144755 (pull request #65)

Missing NETUTILS_HTTPD_PATH added to Kconfig

Approved-by: Gregory Nutt

The CONFIG_NETUTILS_HTTPD_PATH constant is used by httpd_mmap.c and httpd_sendfile.c but It was not present in Kconfig menu.

Remove unused variable

Approved-by: Gregory Nutt

Add platform files for nucleo-f334r8

Approved-by: Gregory Nutt

strcasecmp, strncasecmp, bzero, bcmp, and bcopy should be defined in strings.h, not string.h.  bzero, bcmp, and bcopy are legacy functions; the contemporary counterparts should be used instead.

NSH ls command: if node is a symobolic link, use readlink() to get and the display the target of the symblic link.