Petitboot v1.3.2 & v1.2.7 released

[Samuel Mendoza-Jonas]

Petitboot v1.3.2 and v1.2.7 have been tagged.

v1.3.2 and v1.2.7 both contain the following new fixes:

- discover/platform-powerpc: Reject bootdevs with empty UUIDs
	This fixes an NVRAM parsing issue that could lead to a segfault in the
	ncurses UI. v1.2.7 also fixes this for old-style bootdev parameters.

- ui/ncurses: Spin child to ensure autoboot cancelled on exit
	Avoids the scenario where a user could exit the UI and have the
	pb-discover server still autoboot from underneath them.

- ui/ncurses: Make server connect message more clear

v1.3.2 also contains two significant changes:

- discover/platform-powerpc: Deprecate petitboot,bootdev parameter
	Not user-visible but cleans up NVRAM parameters slightly.

- Support HTTP(S) proxies when downloading resources
	Allows the user to set HTTP(S) proxies for use when loading config or
	boot files (for example).