protected grep from alias, join some sed commands and don't load profile if not needed

[glhez]

Hello,

I've pushed 3 commits:

• A protection against grep alias; if you do alias grep='grep --color -Hn', then the $common_plugins local will contains line starting with (standard input):<line number>:.
• An optimisation on sed, to not invoke it several times. This is better for Windows.
• An optimisation on profile, which don't have to be loaded unless -P or --active-profiles is used.

Note: I used a trick of sed, which can remove the \n delimiter. eg: sed -e s/\n/\|/g does the same as tr '\n' '|'. This works on Git for Windows, did not test on a Linux bash.

[mosabua]

@glhez did you test this on Linux and Mac?

[glhez]

Yep. Tested on:

• Linux 4.0.5-gentoo / bash: version 4.3.39(1)-release (x86_64-pc-linux-gnu)
• Windows 7 Pro / bash: 4.3.39(3)-release (x86_64-pc-msys + git version 2.5.0.windows.1)

Don't have a Mac.

I've added two more commit:

• You can replace new line with sed, but it is a bit more complicated than I though.
• The second commit patch this case:

$ mvn v[TAB]
validate   verify <-- (phase)
$ mvn ver[TAB]
verify <-- phase
$ mvn vers[TAB]
versions: <-- goal

Now it display (here under linux):

$ mvn ver
verify     versions:  vertx: <-- phase + goal

Also, I think the elif [[ ${cur} == *:* ]] ; then can be completely done by the last else.

[glhez]

I mainly replaced old commit due to wrong mail being referenced. It is also rebase against master for all that matter.

[glhez]

I'm closing my PR because of the newly drastic change I've made ... and the fact they were never considered since 2015...

You may still read those:

• I've prefixed cd by builtin like Use "builtin cd" instead of just "cd" #92
• I've prefixed sed and grep by command.
• I've used mapfile and shellcheck to the whole file; this avoid use of IFS and make the code easier to read (to me, at least)
• I've used two function rather than a N variables and indirection
• I fixed the way that the completion was reading pom / settings for profile even if it was not needed
• I've applied a consistent indentation of two spaces and use a java-ish syntax (the foobar() { LF } thing)