Merge branch 'develop' into feature/fix-fholgado-issue-59
Increase 'updatetime' setting to 1500ms

Previous 1000ms makes cursor moving very slow.
Merge branch 'feature/fix-fholgado-issue-59' into develop
Merge branch 'develop' into feature/quit-if-MBE-is-last
Quit MBE before the quiting of Vim by using the new 'QuitPre' event

Due to we can not behave exactly the same as the vim does if MBE is the
last open window, we close the MBE window before the quiting to let the
file window handle it itself.
Merge branch 'feature/quit-if-MBE-is-last' into develop
Merge branch 'develop' into feature/refactor-autoupdate
Check existance for some tab scope variables before using it

Variables 't:miniBufExplAutoUpdate' and 't:skipEligibleBuffersCheck' are
initialized in the TabEnter event, but function 'AutoUpdate()' might get
triggered in the other plugin's TabEnter event before ours. At this
point, these variables havn't been initialized yet, the following errors
will rise:

    Error detected while processing function <SNR>38_BufEnterHandler..<SNR>38_AutoUpdate:
    line   27:
    E121: Undefined variable: t:miniBufExplAutoUpdate
    E15: Invalid expression: t:miniBufExplAutoUpdate == 1

and

    Error detected while processing function <SNR>38_BufEnterHandler..<SNR>38_AutoUpdate:
    line   31:
    E121: Undefined variable: t:skipEligibleBuffersCheck
    E15: Invalid expression: t:skipEligibleBuffersCheck == 1
Respect MBE open/close state across all tabs while opening a new tab

If we execute ':MBECloseAll', we may also want MBE to be disabled in the
new tab.
Merge branch 'feature/refactor-autoupdate' into develop