FIX: bug 1107511

Bug 1107511 - [test case]User can not change tag to none in edit case page.

Have no idea what purpose of the deleted lines of code. From the Form used for
validation, tags are retrieved as a list of tag names, so list type restriction
is added and should not be a None.

Change-Id: Id7533b8146f672666c628c6061bacc358e4dc193
REV: avoid submitting empty post to add tags to a case

Change-Id: I1bd1036cd001e6282b97be8df8f8203b69603e1e
FIX: bug 1089238

Bug 1089238 - [Test run]When import into a csv ,or xml file ,it will display
500 error or error

By confirming with QE, this bug till this fix only affects the CSV export.

Change-Id: Ic82d80913b8f67e16887f053cea3c8153ad39353
REV: each URL each line in exported CSV file

Change-Id: Id3f6bac7beb1696fa8c02a4e088ab60f01547b03
REV: optimize export test case runs from run

Change-Id: I13bb744edf796f2f791a44894b33a4bfbb852a06
FIX: bug 1107975

Bug 1107975 - Cannot auto-complete tag name when enter new tag name in a case
page, server error happens

Change-Id: I791121c7c60ba665dd1516bfc110e52da8f024ab
REV: optimize /report/product/<pid>/component/

TCMS-342 [Performance][Report] Optimize /report/<pid>/component/

Change-Id: I9f5e7a0af15736a25e4a607213c04e0a0f170857
REV: optimize /report/product/<pid>/overview/

Change-Id: I282e716b798ed8f9f268ef07970581118dced5e7
FIX: bugfix 1103303

Bug 1103303 - Inserting some Reference Link beginning with a space raises error

Add StripURLField and use it instead of URLField in forms.

Change-Id: Ib2758eaacf17189639152f6b4868709005aeb800
REV: support multiple databases.

[TCMS-315] Add database router to dispatch read and write operation to master and slave globally
[TCMS-318] Configuration in settings module

1. new database router (tcms.core.utils.tcms_router.RWRouter), implements db_for_read, db_for_write and allow_relation
2. product.py adds slave_1 configuration in DATABASE field.
3. 'default' DB is used for writing, others for reading.

Change-Id: I2afe75331be875659326f1809ddefaab299631f3
REV: show testplan runs order by ID desc.

[TCMS-348] [Regression] User would like to see lates run as default when access runs tab on plan page

Change-Id: I7180d249c888bbc1f18136633d3333bd6a4152ec
REV: Raw SQL, master and slave connection selection

[TCMS-317] Raw SQL, master and slave connection selection

According to django database router, create raw sql router for pick up the connection from read/write db server.

Change-Id: I9da02e744653f23346cfc4b6a5df108fc017aed2
REV: remove dead links

Change-Id: I2951db37cac7faa24aa606b6a58f5bee058d7785
REV: optimize /report/product/<pid>/build/

TCMS-411 [Performance][Report] Optimize /report/product/<pid>/build/

Change-Id: I86267cb36fc5cab3c4c4af6ba866547e6e777858
REV: optimize /report/product/<pid>/build/?build=<bid>

TCMS-411 [Performance][Report] Optimize /report/product/<pid>/build/

Change-Id: I0f70765b42e09455c3473b1284cad2911b113ae3
REV: clean raw SQL

Change-Id: Ie4ab94a445524ad0aa47851cbcb23bf6b69933ba
REV: refactor GROUP BY helper method

Change-Id: I0d9b1ff75f683de44f2a736bcaf8fc0f0dcb2865
REV: cache /report/product/<pid>/build/ view

Change-Id: I53560b15fb700ce2edd615cef3a12d4cef0c2faf
REV: refactor code in report/overall views and data

Change-Id: Ib7641915a67afae3cf1d3aa7a8aaba5bb724f8f3
REV: move SQLs into an app-specific sqls.py

Change-Id: Id22bc25a319dbeb29abe51ec3bbdbae5aba44cd2