RFR: Add tabfiles to jcheck configuration [v3]

[Magnus Ihse Bursie]

> The tabfiles setting is just like the files setting, but it lists files in which tabs are allowed.
> 
> (This is to support makefiles)

Magnus Ihse Bursie has updated the pull request incrementally with one additional commit since the last revision:

  Rename "tabfiles" to "ignore-tabs"

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Changes:
  - all: https://git.openjdk.java.net/skara/pull/929/files
  - new: https://git.openjdk.java.net/skara/pull/929/files/d8c4f75d..4aaa659f

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=skara&pr=929&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=skara&pr=929&range=01-02

  Stats: 8 lines in 2 files changed: 0 ins; 0 del; 8 mod
  Patch: https://git.openjdk.java.net/skara/pull/929.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/929/head:pull/929

PR: https://git.openjdk.java.net/skara/pull/929