Makefile: Added publish tag so the book can be published.

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
user-manual-metadata.xml: Sections to handle variable setting added.

Fixes [YOCTO #5507]

I provided further explanation in the "Basic Variable Setting"
section to note that trailing and leading blanks are not stripped
from a value when set (e.g. VARIABLE = " value").

I added a new section "Null and Blank Setting" explaning that setting
a variable to "" and " " are two different things.

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
user-manual-metadata.xml: Edits to "Basic Variable Setting"

Fixes [YOCTO #5507]

I applied some edits from Richard's review to the fix for
handling variable setting.  Moved the new section I created into
the existing "Basic Variable Setting" section.

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
user-manual-metadata.xml: Added varflag for vardepvalueexclude.

Fixes [YOCTO #5897]

Added several new varflags to the existing list in the
"Variable Flags" section.  The key one being the
"vardepvalueexclude" flag.

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
cooker: delVar in removeConfigurationVar

When a variable was removed from a configuration file it was not
removed from memory. This also had the effect of not allowing
to set a new value for the same variable with saveConfigurationVar.

Signed-off-by: Marius Avram <marius.avram@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
hob: fix set_extra_setting function

The function is used to save additional variables in the configuration file
when the user adds a new (key, value) pair from the Settings->Others. There
was a problem though when the function was trying to retrieve an older
instance of EXTRA_SETTINGS from the configuration file. Sometimes its value
was returned as a dictionary and sometimes a string, which caused a crash when
calling ast.literal_eval(). The reason of the problem must be a change in
bitbake's parsing system. The changes will fix this issues.

While analysing this problem I discovered that the variables were not saved
properly in the configuration file after consecutive changes to Settings->Others
because of the way saveConfigurationVar() from cooker.py works. This patch
will also solve this issue.

[YOCTO #5989]

Signed-off-by: Marius Avram <marius.avram@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>